Descriptions of metrics for instance monitoring, node monitoring, advanced monitoring, and performance trend - ApsaraDB for MongoDB

This topic describes the metrics for instance monitoring, node monitoring, advanced monitoring, and Performance Trend in ApsaraDB for MongoDB, and explains the meaning of each metric.

Note

To improve readability, byte units in the console are automatically converted to MB, GB, or TB.

Instance monitoring

Note

For information about the metrics supported by different instance types, see the console.

Metric	Key	Metric name	Metric meaning	Unit	Detailed description	Supported instance types
Disk usage	DiskUsage	disk_usage	Disk usage	%	The percentage of the total disk capacity that is used by the instance. This metric indicates the disk load of the instance. If the disk usage exceeds 80%, change the instance configuration on the instance details page in the console or see Change instance configuration or High disk usage of ApsaraDB for MongoDB instances for solutions.	Standalone Replica set Sharded cluster Serverless
Network traffic	MongoDB_Network	bytes_in	Inbound network traffic	Bytes	-
		bytes_out	Outbound network traffic	Bytes	-
		num_requests	Number of processed requests	count	-
Operation QPS	MongoDB_Opcounters	insert	Insert operations QPS	count	The MongoDB_Opcounters parameter includes all operations received by the instance, regardless of whether they were executed successfully. Batch operations of the Bulk.insert() type are recorded as a single operation. For more granular records, see the MongoDB_Documents metric. For more information, see Opcounters and Repl Opcounters metrics.
		query	Query operations QPS	count
		update	Update operations QPS	count
		delete	Delete operations QPS	count
		getmore	Read operations QPS	count
		command	Protocol command operations QPS	count
Connections	MongoDB_TotalConns	connections_active	Current active connections	count	The number of client connections to the server that are performing operations.
		current_conn	Current connections	count	The total number of client connections to the server. This includes connections established by other nodes in a replica set or connections established between Mongos and shard nodes.
		connections_totalCreated_ps	Total new connections per second	count	-	Standalone Replica set Sharded cluster
		connections_available	Current available connections	count	-
Connection usage	ConnectionUsage	conn_usage	Connection usage	%	The ratio of the current number of connections to the maximum number of connections for the instance. This metric indicates the connection load of the instance. The maximum number of connections varies based on the instance type that you purchase. For more information, see Instance types. To increase the connection limit, change the instance configuration on the instance details page in the console. You can also adjust the number of client connections. For more information, see Change instance configuration or Query and limit the number of connections.
CPU usage	CpuUsage	cpu_usage	CPU usage	%	The sum of system CPU usage and user CPU usage. This metric indicates the service load of the instance. High CPU usage can cause slow data reads and writes, affecting normal services. For troubleshooting, see High CPU usage of ApsaraDB for MongoDB instances.
	MongoDB_CpuDetail	cpu_sys	System CPU usage	%	-
	MongoDB_CpuDetail	cpu_user	User CPU usage	%	-
Memory usage	MemoryUsage	mem_usage	Memory usage	%	Memory is mainly occupied by the WiredTiger storage engine, client connections, and request processing. For information about the causes of high memory usage and optimization strategies, see High memory usage of ApsaraDB for MongoDB instances.
IOPS usage	MongoDB_IOPS	iops	IOPS usage	times/s	Replica set and sharded cluster instances of ApsaraDB for MongoDB 4.2 that use cloud disks do not support viewing IOPS usage and IOPS usage rate. The data_iops and log_iops metrics from older monitoring versions are now merged into iops.
IOPS usage rate	IOPSUsage	iops_usage	IOPS usage rate	%	The ratio of the instance's IOPS usage to the maximum IOPS of the current instance type. This metric indicates the service load of the instance. If the IOPS usage of a MongoDB instance reaches or approaches 100%, it can cause slow service responses or even service unavailability. High IOPS usage of ApsaraDB for MongoDB instances describes how to view the IOPS usage rate and explains the causes of high IOPS usage and optimization strategies. Note Replica set and sharded cluster instances of ApsaraDB for MongoDB 4.2 that use cloud disks do not support viewing IOPS usage and IOPS usage rate.
Disk space usage	MongoDB_DetailedSpaceUsage	ins_size	Used disk space	Bytes	For local disk instances, the used disk space is the sum of the used data disk space and log disk space. For cloud disk instances, the used disk space also includes the space occupied by file system metadata.
		data_size	Used data disk space	Bytes	The space used by the data disk (excluding the local database). This mainly includes physical data files starting with "collection", physical index files starting with "index", and some physical metadata files, such as WiredTiger.wt.
		log_size	Used log disk space	Bytes	The physical size of the local database.
Operation details	MongoDB_OperationDetails	operation_exactIDCount_ps	Number of count operations for a specific ID	count	The number of single update operations that use _id instead of a shard key on a sharded collection whose data is distributed across multiple shards. In current versions, this causes a traversal of all chunks in the instance. If the number of chunks is large, it may lead to full CPU utilization and affect instance performance.
		operation_scanAndOrder_ps	Number of sort operations without an index	count	The number of sorted queries that cannot use an index to perform the sort operation. A large number can degrade instance performance. Based on your business query conditions, see Best practices for creating indexes in ApsaraDB for MongoDB for solutions.
		operation_writeConflicts_ps	Number of write conflicts	count	The number of queries that encountered write conflicts. A small number of write conflicts generally does not have a significant impact. However, many write conflicts can lead to decreased database performance.
BPS	MongoDB_Disk_Detail	read_io_bandwidth_mbps	Disk read throughput	MB/s	-
		write_io_bandwidth_mbps	Disk write throughput	MB/s	-
		io_bandwidth_mbps	Total disk throughput	MB/s	The sum of disk read throughput and disk write throughput.
Transaction operands	MongoDB_Transactions	trans_totalPrepared_ps	Number of prepared transactions	count	-	Replica set Sharded cluster (shard nodes only)
		trans_totalPreparedThenCommited_ps	Number of prepared transactions that were successfully committed	count	-
		trans_totalPreparedThenAborted_ps	Number of prepared transactions that were successfully rolled back	count	-
		trans_totalStarted_ps	Number of started transactions	count	-	Standalone Replica set Sharded cluster
		trans_totalCommited_ps	Number of successfully committed transactions	count	-
		trans_totalAborted_ps	Number of successfully rolled back transactions	count	-
Cursors	MongoDB_AllCursors	total_open	Number of currently open cursors	count	-
		timed_out	Number of cursors closed due to timeout	count	If this value is large, check the client-side business code that processes data.
		job_cursors_closed	Number of cursors closed due to session closure	count	-
		pinned_open	Number of currently open and in-use cursors	count	For example, find or getMore operations pin a cursor to prevent it from being deleted while fetching the next batch of results, and unpin it after returning the results.
		noTimeout_open	Number of currently open and non-timed-out cursors	count	The number of open and non-timed-out cursors that use the noCursorTimeout option. This option prevents a cursor from timing out after a period of inactivity. However, the noCursorTimeout configuration is limited by the session timeout. For more information, see the documentation.	Standalone Replica set Sharded cluster (shard and Configserver nodes only)
WiredTiger	MongoDB_Wt_Cache	bytes_read_into_cache	Bytes read into cache	Bytes	The number of bytes of data read from disk into the WiredTiger cache.
		bytes_written_from_cache	Bytes written from cache	Bytes	The number of bytes of data written from the WiredTiger cache to disk.
		maximum_bytes_configured	Maximum cache size	Bytes	The maximum number of bytes configured for the WiredTiger cache. For compatibility and security, ApsaraDB for MongoDB sets the CacheSize of the WiredTiger storage engine to about 60% of the requested instance memory size. For more information, see High memory usage of ApsaraDB for MongoDB instances.
WT concurrent transactions	MongoDB_Wt_Concurrent_Trans	write_concurrent_trans_out	Current concurrent write transactions	count	Before V7.0, the limit for concurrent read and write transactions for an instance was 128. If the availability parameter was 0 for a long time, it could indicate an overload. Starting from V7.0, MongoDB uses a default algorithm to dynamically adjust the maximum number of concurrent storage engine transactions to optimize database throughput during overload. An availability parameter of 0 for a long time does not necessarily indicate an overload. For more information, see the documentation.
		write_concurrent_trans_available	Available concurrent write transactions	count
		read_concurrent_trans_out	Current concurrent read transactions	count
		read_concurrent_trans_available	Available concurrent read transactions	count
WiredTigerUsage	MongoDB_WTCacheUsage	wt_cache_dirty_usage	WiredTiger dirty cache usage	%	For more information, see High memory usage of ApsaraDB for MongoDB instances.
WiredTigerUsage	MongoDB_WTCacheUsage	wt_cache_usage	WiredTiger cache usage	%
Average response time	MongoDB_RT	avg_rt	Total average response time	μs	-
		reads_avg_rt	Average response time for read operations	μs	-
		writes_avg_rt	Average response time for write operations	μs	-
		commands_avg_rt	Average response time for command operations	μs	-
		trans_avg_rt	Average response time for transaction operations	μs	-
Number of affected documents	MongoDB_Documents	document_deleted_ps	Number of deleted documents	count	-
		document_inserted_ps	Number of inserted documents	count	-
		document_returned_ps	Number of returned documents	count	-
		document_updated_ps	Number of updated documents	count	-
GlobalLock	MongoDB_GlobalLocks	gl_ac_readers	Number of active client connections performing read operations	count	-
		gl_ac_writers	Number of active client connections performing write operations	count	-
		gl_cq_writers	Number of operations queued for a write lock	count	-
		gl_cq_readers	Number of operations queued for a read lock	count	-
		gl_cq_total	Total number of operations queued for a lock	count	The sum of the number of operations queued for a write lock and the number of operations queued for a read lock. A large value indicates that client operations may be delayed, which can affect application response time.
Number of scanned index entries and documents in queries	MongoDB_QueryExecutors	queryExecutor_scannedObject_ps	Number of documents scanned by queries	count	The total number of documents scanned during query execution and query plan evaluation. This is the same as `explain()` in the `totalDocsExamined` output. A large number indicates that the database needs to scan many non-indexed entries. Create an index for fields with a large scan count.
Number of scanned index entries and documents in queries	MongoDB_QueryExecutors	queryExecutor_scanned_ps	Number of index entries scanned by queries	count	The total number of index entries scanned during query execution and query plan evaluation. This is the same as `totalKeysExamined` in the `explain()` output. If this value is large but the number of returned documents is small, it indicates that the database scanned many index keys to get the result documents. This means the index is not efficient. Adjust the index or create other indexes.
TTL	MongoDB_TTLs	ttl_deletedDocuments_ps	Number of documents deleted due to TTL index	count	A large value indicates that many documents are being deleted, which may affect instance performance. For more information, see the documentation.
TTL	MongoDB_TTLs	ttl_passes_ps	Number of times the background TTL thread performs deletions	count	The total number of times the TTL background process checks for expired documents. Each time it checks, the TTL monitor attempts to delete as many candidate documents as possible from all TTL indexes.
Repl Opcounters	MongoDB_ReplOpcounters	repl_command	Number of Command operands in the replica set	count	During replication, MongoDB serializes operations, which may affect the count of each operation. Therefore, the values of the MongoDB_ReplOpcounters and MongoDB_Opcounters counters may differ. For more information, see Opcounters and Repl Opcounters metrics.
		repl_delete	Number of Delete command operands in the replica set	count
		repl_getmore	Number of Getmore command operands in the replica set	count
		repl_insert	Number of Insert command operands in the replica set	count
		repl_query	Number of Query command operands in the replica set	count
		repl_update	Number of Update command operands in the replica set	count
Eviction scan count	MongoDB_WtCacheHPCheckEntriesWalked	wiredTiger_cache_hazardPointerCheckEntriesWalked	Number of items in the hazard pointer array scanned during eviction	count	Number of page evictions blocked by hazard pointers during eviction.
Lock Acquisitions	MongoDB_WtLockAcquisitions	wt_checkPoint_lock	Number of checkpoint lock acquisitions	count	-
		wt_dhandle_read_lock	Number of data handle read lock acquisitions	count	If an instance has too many databases and collections, client requests may have to wait a long time for a handle lock. This affects instance performance. For more information, see Instance stuttering or abnormality caused by too many databases and collections.
		wt_dhandle_write_lock	Number of data handle write lock acquisitions	count
		wt_metadata_lock	Number of metadata lock acquisitions	count
		wt_schema_lock	Number of schema lock acquisitions	count	Frequent deletion and creation of databases, collections, or indexes, and having too many databases and collections can lead to higher schemaLock overhead, affecting instance performance. For more information, see Instance stuttering or abnormality caused by too many databases and collections.
		wt_table_read_lock	Number of table read lock acquisitions	count	-
		wt_table_write_lock	Number of table write lock acquisitions	count	-
		wt_txn_global_read_lock	Number of transaction global read lock acquisitions	count	-
		wt_txn_global_write_lock	Number of transaction global write lock acquisitions	count	-
BPS usage rate	MongoDB_MbpsUsage	total_mbps_usage	Disk read/write bandwidth usage rate	%	The ratio of the instance's total disk throughput to the maximum BPS of the instance. This metric indicates the service load of the instance. If the BPS usage of a MongoDB instance reaches or approaches 100%, it can cause slow service responses or even service unavailability. For more information about cloud disk BPS, see Instance types. Note Only supported for cloud disk instances.	Standalone Replica set Sharded cluster (shard nodes only)
Primary-secondary latency	MongoDB_Repl_Lag	repl_lag	Data synchronization latency between primary and secondary nodes	s	The heartbeat interval between replica set members is 2s. Therefore, a repl_lag value between -2 and 2 is normal for replica set instances, and for shard and Configserver nodes of sharded cluster instances. The repl_lag value for a secondary node can be negative. This does not mean that the secondary node is ahead of the primary node. To get the latest primary-secondary latency status of a replica set, run rs.printSecondaryReplicationInfo() on the primary node.	ReplicaSet Sharded cluster (Shard and ConfigServer only)
Oplog retention period	MongoDB_OplogTimeInterval	oplog_time_interval	Oplog retention period	Hours	For versions 4.4 and later, modify the storage.oplogMinRetentionHours parameter on the instance product page.	ReplicaSet Sharded cluster (Shard and ConfigServer only)
moveChunk	MongoDB_MoveChunks	moveChunk_donor_started_ps	The number of times the current node acts as a migration source.	Count	This value increases regardless of whether the migration is successful.	Sharded cluster (Shard only)
moveChunk	MongoDB_MoveChunks	moveChunk_recip_stared_ps	The number of times the current node is the target for a chunk migration.	Count		Sharded cluster (Shard only)
Items per access	-	sl_qps	Accesses per second	Count	-	Serverless instance
Query executor information	MongoDB_QueryExecutors	collscans_nontailable	Number of full table scans for non-tailable cursors	Count	-	ReplicaSet Sharded cluster (excluding mongos)
Query executor information	MongoDB_QueryExecutors	collscans_total	Total number of full table scans	Item	-	ReplicaSet Sharded cluster (excluding mongos)
Number of databases and tables	MongoDB_CollectionNums	admin_user_coll	Number of user tables in the admin database	Count	-	ReplicaSet versions 4.2 and earlier Sharded clusters
Number of assertions	MongoDB_Asserts	Regular	Normal level	Count	The number of assertions that passed.	Single node ReplicaSet Sharded cluster
		warning	Warning level	Count	The number of warning-level assertions. This value is always 0.
		msg	Message level	Count	The number of message-level assertions.
		user	User level	Item	The number of user-level assertions.
Number of data handles	MongoDB_DataHandle	opened_fd_num	Active handle count	Item	The number of active connection data handles in the WiredTiger cache.	Single node ReplicaSet Sharded cluster
		closed_fd_num	Number of closed handles	Count	The number of closed data handles for connections scanned in the WiredTiger cache.
		opened_fd_mem	Memory used by active handles	MB	The memory used by currently active connection data handles in the WiredTiger cache.
Operation latency	MongoDB_Latencies	reads_latency_ps	Latency of successful read requests	us	The latency of all successful read requests.	Single node ReplicaSet Sharded cluster
		writes_latency_ps	Successful write request latency	us	The latency of all successful write requests. The unit is us.
		commands_latency_ps	Latency of successful command operations	us	The latency of all successful requests for command operations, in us.
		trans_latency_ps	Latency of successful transaction requests	us	The time it takes for all successful requests in a transaction to be processed. The unit is us.
TCMalloc memory fragmentation ratio	MongoDB_TcmallocCacheMemRatio	tcmalloc_cache_mem_ratio	TCMalloc memory fragmentation ratio	%	-	Single node ReplicaSet Sharded cluster
Average write time for follows	MongoDB_GetLastErrorWtime	metrics_getLastError_avg_wtime	Average time for write follow operations	ms	The average time to perform a write-follow operation.	Single node ReplicaSet Sharded cluster (mongod only)
Average write time for follows	MongoDB_GetLastErrorWtime	metrics_getLastError_wtimeouts	Timeouts for write and follow operations	Times	Number of write concern operations that exceeded the `wtimeout` threshold.	Single node ReplicaSet Sharded cluster
Replication buffer size	MongoDB_Repl_Buffer	repl_buffer_size	Current replication buffer size	MB	The current size of the replication buffer in the ReplicaSet.	ReplicaSet sharded cluster
Replication buffer size	MongoDB_Repl_Buffer	repl_buffer_max_size	Maximum replication buffer size	MB	The maximum size of the replication buffer in the ReplicaSet.	ReplicaSet sharded cluster
WiredTiger cache page evictions	MongoDB_WtCacheEviction	pages_selected_count	Number of pages that are forcibly evicted	Count	-	Single node ReplicaSet Sharded cluster
		pages_selected_unable_to_evict_count	The number of pages that cannot be evicted.	Count	-
		hazard_pointer_blocked_page_eviction	Number of page evictions blocked by hazard pointers	Count	-
		max_page_size	The maximum page size encountered during the page eviction process.	MB	-
		pages_evicted_by_application_threads	Number of pages in the WiredTiger cache evicted by user threads	Item	-
moveChunk	MongoDB_MoveChunks	moveChunk_deleter_task	Number of pending and running chunk range deletion tasks	Count	-	Sharded cluster
LockAcquisitions	MongoDB_WtLockAcquisitions	wt_checkPoint_lock	Number of checkpoint lock acquisitions in the WiredTiger cache	Item	-	Single node ReplicaSet Sharded cluster
		wt_dhandle_read_lock	The number of read locks acquired for data handles in the WiredTiger cache.	Count	-
		wt_dhandle_write_lock	The number of times a write lock is acquired for a data handle in the WiredTiger cache.	Count	-
		wt_metadata_lock	The number of metadata locks acquired in the WiredTiger cache	Count	-
		wt_schema_lock	The number of schema locks acquired in the WiredTiger cache.	Count	-
		wt_table_read_lock	The number of table read locks acquired in the WiredTiger cache.	Count	-
		wt_table_write_lock	The number of table write locks acquired in the WiredTiger cache.	Count	-
		wt_txn_global_read_lock	The number of times the global read lock is acquired in the WiredTiger cache.	Count	-
		wt_txn_global_write_lock	The number of global write locks acquired in the WiredTiger cache.	Count	-
Thread yielding	MongoDB_WtCache_Thread_Yield	page_acquire_eviction_blocked	Number of times blocked waiting for page eviction	Count	-	Single node ReplicaSet Sharded cluster
		page_acquire_locked_blocked	Number of waits for a locked target page	Times	-
		page_acquire_time_sleeping	Total thread sleep duration when fetching a page	us	-
WiredTigerUsage	MongoDB_WTCacheUsage	wt_cache_updates_usage	WiredTiger update cache utilization	%	The proportion of the maximum cache size in bytes that is allocated for update operations.	Single node ReplicaSet Sharded cluster
Classic multi-planner execution statistics	MongoDB_MultiPlanner_Worker	metrics_query_multiplanner_classicworks	Total number of tasks	Count	The total number of tasks executed by the classic multi-planner.	ReplicaSet Sharded cluster (mongod only)
Logical session cache information	MongoDB_LogicalSession	active_sessions_count	Number of logical sessions in the cache	Item	The total number of logical sessions in the cache since the last refresh.	ReplicaSet sharded cluster

Node monitoring (formerly basic monitoring)

Note

For information about the metrics supported by different instance types, see the console.

Metric	Key	Metric name	Metric meaning	Unit	Detailed description	Supported instance types
Disk usage	DiskUsage	disk_usage	Disk usage	%	The percentage of the total disk capacity that is used by the instance. This metric indicates the disk load of the instance. If the disk usage exceeds 80%, change the instance configuration on the instance details page in the console or see Change instance configuration or High disk usage of ApsaraDB for MongoDB instances for solutions.	Standalone Replica set Sharded cluster Serverless
Network traffic	MongoDB_Network	bytes_in	Inbound network traffic	Bytes	-
		bytes_out	Outbound network traffic	Bytes	-
		num_requests	Number of processed requests	count	-
Operation QPS	MongoDB_Opcounters	insert	Insert operations QPS	count	The MongoDB_Opcounters parameter includes all operations received by the instance, regardless of whether they were executed successfully. Batch operations of the Bulk.insert() type are recorded as a single operation. For more granular records, see the MongoDB_Documents metric. For more information, see Opcounters and Repl Opcounters metrics.
		query	Query operations QPS	count
		update	Update operations QPS	count
		delete	Delete operations QPS	count
		getmore	Read operations QPS	count
		command	Protocol command operations QPS	count
Connections	MongoDB_TotalConns	connections_active	Current active connections	count	The number of client connections to the server that are performing operations.
		current_conn	Current connections	count	The total number of client connections to the server. This includes connections established by other nodes in a replica set or connections established between Mongos and shard nodes.
		connections_totalCreated_ps	Total new connections per second	count	-	Standalone Replica set Sharded cluster
		connections_available	Current available connections	count	-
Connection usage	ConnectionUsage	conn_usage	Connection usage	%	The ratio of the current number of connections to the maximum number of connections for the instance. This metric indicates the connection load of the instance. The maximum number of connections varies based on the instance type that you purchase. For more information, see Instance types. To increase the connection limit, change the instance configuration on the instance details page in the console. You can also adjust the number of client connections. For more information, see Change instance configuration or Query and limit the number of connections.
CPU usage	CpuUsage	cpu_usage	CPU usage	%	The sum of system CPU usage and user CPU usage. This metric indicates the service load of the instance. High CPU usage can cause slow data reads and writes, affecting normal services. For troubleshooting, see High CPU usage of ApsaraDB for MongoDB instances.
	MongoDB_CpuDetail	cpu_sys	System CPU usage	%	-
	MongoDB_CpuDetail	cpu_user	User CPU usage	%	-
Memory usage	MemoryUsage	mem_usage	Memory usage	%	Memory is mainly occupied by the WiredTiger storage engine, client connections, and request processing. For information about the causes of high memory usage and optimization strategies, see High memory usage of ApsaraDB for MongoDB instances.
IOPS usage	MongoDB_IOPS	iops	IOPS usage	times/s	Replica set and sharded cluster instances of ApsaraDB for MongoDB 4.2 that use cloud disks do not support viewing IOPS usage and IOPS usage rate. The data_iops and log_iops metrics from older monitoring versions are now merged into iops.
IOPS usage rate	IOPSUsage	iops_usage	IOPS usage rate	%	The ratio of the instance's IOPS usage to the maximum IOPS of the current instance type. This metric indicates the service load of the instance. If the IOPS usage of a MongoDB instance reaches or approaches 100%, it can cause slow service responses or even service unavailability. High IOPS usage of ApsaraDB for MongoDB instances describes how to view the IOPS usage rate and explains the causes of high IOPS usage and optimization strategies. Note Replica set and sharded cluster instances of ApsaraDB for MongoDB 4.2 that use cloud disks do not support viewing IOPS usage and IOPS usage rate.
Disk space usage	MongoDB_DetailedSpaceUsage	ins_size	Used disk space	Bytes	For local disk instances, the used disk space is the sum of the used data disk space and log disk space. For cloud disk instances, the used disk space also includes the space occupied by file system metadata.
		data_size	Used data disk space	Bytes	The space used by the data disk (excluding the local database). This mainly includes physical data files starting with "collection", physical index files starting with "index", and some physical metadata files, such as WiredTiger.wt.
		log_size	Used log disk space	Bytes	The physical size of the local database.
Operation details	MongoDB_OperationDetails	operation_exactIDCount_ps	Number of count operations for a specific ID	count	The number of single update operations that use _id instead of a shard key on a sharded collection whose data is distributed across multiple shards. In current versions, this causes a traversal of all chunks in the instance. If the number of chunks is large, it may lead to full CPU utilization and affect instance performance.
		operation_scanAndOrder_ps	Number of sort operations without an index	count	The number of sorted queries that cannot use an index to perform the sort operation. A large number can degrade instance performance. Based on your business query conditions, see Best practices for creating indexes in ApsaraDB for MongoDB for solutions.
		operation_writeConflicts_ps	Number of write conflicts	count	The number of queries that encountered write conflicts. A small number of write conflicts generally does not have a significant impact. However, many write conflicts can lead to decreased database performance.
BPS	MongoDB_Disk_Detail	read_io_bandwidth_mbps	Disk read throughput	MB/s	-
		write_io_bandwidth_mbps	Disk write throughput	MB/s	-
		io_bandwidth_mbps	Total disk throughput	MB/s	The sum of disk read throughput and disk write throughput.
Transaction operands	MongoDB_Transactions	trans_totalPrepared_ps	Number of prepared transactions	count	-	Replica set Sharded cluster (shard nodes only)
		trans_totalPreparedThenCommited_ps	Number of prepared transactions that were successfully committed	count	-
		trans_totalPreparedThenAborted_ps	Number of prepared transactions that were successfully rolled back	count	-
		trans_totalStarted_ps	Number of started transactions	count	-	Standalone Replica set Sharded cluster
		trans_totalCommited_ps	Number of successfully committed transactions	count	-
		trans_totalAborted_ps	Number of successfully rolled back transactions	count	-
Cursors	MongoDB_AllCursors	total_open	Number of currently open cursors	count	-
		timed_out	Number of cursors closed due to timeout	count	If this value is large, check the client-side business code that processes data.
		job_cursors_closed	Number of cursors closed due to session closure	count	-
		pinned_open	Number of currently open and in-use cursors	count	For example, find or getMore operations pin a cursor to prevent it from being deleted while fetching the next batch of results, and unpin it after returning the results.
		noTimeout_open	Number of currently open and non-timed-out cursors	count	The number of open and non-timed-out cursors that use the noCursorTimeout option. This option prevents a cursor from timing out after a period of inactivity. However, the noCursorTimeout configuration is limited by the session timeout. For more information, see the documentation.	Standalone Replica set Sharded cluster (shard and Configserver nodes only)
WiredTiger	MongoDB_Wt_Cache	bytes_read_into_cache	Bytes read into cache	Bytes	The number of bytes of data read from disk into the WiredTiger cache.
		bytes_written_from_cache	Bytes written from cache	Bytes	The number of bytes of data written from the WiredTiger cache to disk.
		maximum_bytes_configured	Maximum cache size	Bytes	The maximum number of bytes configured for the WiredTiger cache. For compatibility and security, ApsaraDB for MongoDB sets the CacheSize of the WiredTiger storage engine to about 60% of the requested instance memory size. For more information, see High memory usage of ApsaraDB for MongoDB instances.
WT concurrent transactions	MongoDB_Wt_Concurrent_Trans	write_concurrent_trans_out	Current concurrent write transactions	count	Before V7.0, the limit for concurrent read and write transactions for an instance was 128. If the availability parameter was 0 for a long time, it could indicate an overload. Starting from V7.0, MongoDB uses a default algorithm to dynamically adjust the maximum number of concurrent storage engine transactions to optimize database throughput during overload. An availability parameter of 0 for a long time does not necessarily indicate an overload. For more information, see the documentation.
		write_concurrent_trans_available	Available concurrent write transactions	count
		read_concurrent_trans_out	Current concurrent read transactions	count
		read_concurrent_trans_available	Available concurrent read transactions	count
WiredTigerUsage	MongoDB_WTCacheUsage	wt_cache_dirty_usage	WiredTiger dirty cache usage	%	For more information, see High memory usage of ApsaraDB for MongoDB instances.
WiredTigerUsage	MongoDB_WTCacheUsage	wt_cache_usage	WiredTiger cache usage	%
Average response time	MongoDB_RT	avg_rt	Total average response time	μs	-
		reads_avg_rt	Average response time for read operations	μs	-
		writes_avg_rt	Average response time for write operations	μs	-
		commands_avg_rt	Average response time for command operations	μs	-
		trans_avg_rt	Average response time for transaction operations	μs	-
Number of affected documents	MongoDB_Documents	document_deleted_ps	Number of deleted documents	count	-
		document_inserted_ps	Number of inserted documents	count	-
		document_returned_ps	Number of returned documents	count	-
		document_updated_ps	Number of updated documents	count	-
GlobalLock	MongoDB_GlobalLocks	gl_ac_readers	Number of active client connections performing read operations	count	-
		gl_ac_writers	Number of active client connections performing write operations	count	-
		gl_cq_writers	Number of operations queued for a write lock	count	-
		gl_cq_readers	Number of operations queued for a read lock	count	-
		gl_cq_total	Total number of operations queued for a lock	count	The sum of the number of operations queued for a write lock and the number of operations queued for a read lock. A large value indicates that client operations may be delayed, which can affect application response time.
Number of scanned index entries and documents in queries	MongoDB_QueryExecutors	queryExecutor_scannedObject_ps	Number of documents scanned by queries	count	The total number of documents scanned during query execution and query plan evaluation. This is the same as `explain()` in the `totalDocsExamined` output. A large number indicates that the database needs to scan many non-indexed entries. Create an index for fields with a large scan count.
Number of scanned index entries and documents in queries	MongoDB_QueryExecutors	queryExecutor_scanned_ps	Number of index entries scanned by queries	count	The total number of index entries scanned during query execution and query plan evaluation. This is the same as `totalKeysExamined` in the `explain()` output. If this value is large but the number of returned documents is small, it indicates that the database scanned many index keys to get the result documents. This means the index is not efficient. Adjust the index or create other indexes.
TTL	MongoDB_TTLs	ttl_deletedDocuments_ps	Number of documents deleted due to TTL index	count	A large value indicates that many documents are being deleted, which may affect instance performance. For more information, see the documentation.
TTL	MongoDB_TTLs	ttl_passes_ps	Number of times the background TTL thread performs deletions	count	The total number of times the TTL background process checks for expired documents. Each time it checks, the TTL monitor attempts to delete as many candidate documents as possible from all TTL indexes.
Repl Opcounters	MongoDB_ReplOpcounters	repl_command	Number of Command operands in the replica set	count	During replication, MongoDB serializes operations, which may affect the count of each operation. Therefore, the values of the MongoDB_ReplOpcounters and MongoDB_Opcounters counters may differ. For more information, see Opcounters and Repl Opcounters metrics.
		repl_delete	Number of Delete command operands in the replica set	count
		repl_getmore	Number of Getmore command operands in the replica set	count
		repl_insert	Number of Insert command operands in the replica set	count
		repl_query	Number of Query command operands in the replica set	count
		repl_update	Number of Update command operands in the replica set	count
Eviction scan count	MongoDB_WtCacheHPCheckEntriesWalked	wiredTiger_cache_hazardPointerCheckEntriesWalked	Number of items in the hazard pointer array scanned during eviction	count	Number of page evictions blocked by hazard pointers during eviction.
Lock Acquisitions	MongoDB_WtLockAcquisitions	wt_checkPoint_lock	Number of checkpoint lock acquisitions	count	-
		wt_dhandle_read_lock	Number of data handle read lock acquisitions	count	If an instance has too many databases and collections, client requests may have to wait a long time for a handle lock. This affects instance performance. For more information, see Instance stuttering or abnormality caused by too many databases and collections.
		wt_dhandle_write_lock	Number of data handle write lock acquisitions	count
		wt_metadata_lock	Number of metadata lock acquisitions	count
		wt_schema_lock	Number of schema lock acquisitions	count	Frequent deletion and creation of databases, collections, or indexes, and having too many databases and collections can lead to higher schemaLock overhead, affecting instance performance. For more information, see Instance stuttering or abnormality caused by too many databases and collections.
		wt_table_read_lock	Number of table read lock acquisitions	count	-
		wt_table_write_lock	Number of table write lock acquisitions	count	-
		wt_txn_global_read_lock	Number of transaction global read lock acquisitions	count	-
		wt_txn_global_write_lock	Number of transaction global write lock acquisitions	count	-
BPS usage rate	MongoDB_MbpsUsage	total_mbps_usage	Disk read/write bandwidth usage rate	%	The ratio of the instance's total disk throughput to the maximum BPS of the instance. This metric indicates the service load of the instance. If the BPS usage of a MongoDB instance reaches or approaches 100%, it can cause slow service responses or even service unavailability. For more information about cloud disk BPS, see Instance types. Note Only supported for cloud disk instances.	Standalone Replica set Sharded cluster (shard nodes only)
Primary-secondary latency	MongoDB_Repl_Lag	repl_lag	Data synchronization latency between primary and secondary nodes	s	The heartbeat interval between replica set members is 2s. Therefore, a repl_lag value between -2 and 2 is normal for replica set instances, and for shard and Configserver nodes of sharded cluster instances. The repl_lag value for a secondary node can be negative. This does not mean that the secondary node is ahead of the primary node. To get the latest primary-secondary latency status of a replica set, run rs.printSecondaryReplicationInfo() on the primary node.	ReplicaSet Sharded cluster (Shard and ConfigServer only)
Oplog retention period	MongoDB_OplogTimeInterval	oplog_time_interval	Oplog retention period	Hours	For versions 4.4 and later, modify the storage.oplogMinRetentionHours parameter on the instance product page.	ReplicaSet Sharded cluster (Shard and ConfigServer only)
moveChunk	MongoDB_MoveChunks	moveChunk_donor_started_ps	The number of times the current node acts as a migration source.	Count	This value increases regardless of whether the migration is successful.	Sharded cluster (Shard only)
moveChunk	MongoDB_MoveChunks	moveChunk_recip_stared_ps	The number of times the current node is the target for a chunk migration.	Count		Sharded cluster (Shard only)
Items per access	-	sl_qps	Accesses per second	Count	-	Serverless instance
Query executor information	MongoDB_QueryExecutors	collscans_nontailable	Number of full table scans for non-tailable cursors	Count	-	ReplicaSet Sharded cluster (excluding mongos)
Query executor information	MongoDB_QueryExecutors	collscans_total	Total number of full table scans	Item	-	ReplicaSet Sharded cluster (excluding mongos)
Number of databases and tables	MongoDB_CollectionNums	admin_user_coll	Number of user tables in the admin database	Count	-	ReplicaSet versions 4.2 and earlier Sharded clusters
Number of assertions	MongoDB_Asserts	Regular	Normal level	Count	The number of assertions that passed.	Single node ReplicaSet Sharded cluster
		warning	Warning level	Count	The number of warning-level assertions. This value is always 0.
		msg	Message level	Count	The number of message-level assertions.
		user	User level	Item	The number of user-level assertions.
Number of data handles	MongoDB_DataHandle	opened_fd_num	Active handle count	Item	The number of active connection data handles in the WiredTiger cache.	Single node ReplicaSet Sharded cluster
		closed_fd_num	Number of closed handles	Count	The number of closed data handles for connections scanned in the WiredTiger cache.
		opened_fd_mem	Memory used by active handles	MB	The memory used by currently active connection data handles in the WiredTiger cache.
Operation latency	MongoDB_Latencies	reads_latency_ps	Latency of successful read requests	us	The latency of all successful read requests.	Single node ReplicaSet Sharded cluster
		writes_latency_ps	Successful write request latency	us	The latency of all successful write requests. The unit is us.
		commands_latency_ps	Latency of successful command operations	us	The latency of all successful requests for command operations, in us.
		trans_latency_ps	Latency of successful transaction requests	us	The time it takes for all successful requests in a transaction to be processed. The unit is us.
TCMalloc memory fragmentation ratio	MongoDB_TcmallocCacheMemRatio	tcmalloc_cache_mem_ratio	TCMalloc memory fragmentation ratio	%	-	Single node ReplicaSet Sharded cluster
Average write time for follows	MongoDB_GetLastErrorWtime	metrics_getLastError_avg_wtime	Average time for write follow operations	ms	The average time to perform a write-follow operation.	Single node ReplicaSet Sharded cluster (mongod only)
Average write time for follows	MongoDB_GetLastErrorWtime	metrics_getLastError_wtimeouts	Timeouts for write and follow operations	Times	Number of write concern operations that exceeded the `wtimeout` threshold.	Single node ReplicaSet Sharded cluster
Replication buffer size	MongoDB_Repl_Buffer	repl_buffer_size	Current replication buffer size	MB	The current size of the replication buffer in the ReplicaSet.	ReplicaSet sharded cluster
Replication buffer size	MongoDB_Repl_Buffer	repl_buffer_max_size	Maximum replication buffer size	MB	The maximum size of the replication buffer in the ReplicaSet.	ReplicaSet sharded cluster
WiredTiger cache page evictions	MongoDB_WtCacheEviction	pages_selected_count	Number of pages that are forcibly evicted	Count	-	Single node ReplicaSet Sharded cluster
		pages_selected_unable_to_evict_count	The number of pages that cannot be evicted.	Count	-
		hazard_pointer_blocked_page_eviction	Number of page evictions blocked by hazard pointers	Count	-
		max_page_size	The maximum page size encountered during the page eviction process.	MB	-
		pages_evicted_by_application_threads	Number of pages in the WiredTiger cache evicted by user threads	Item	-
moveChunk	MongoDB_MoveChunks	moveChunk_deleter_task	Number of pending and running chunk range deletion tasks	Count	-	Sharded cluster
LockAcquisitions	MongoDB_WtLockAcquisitions	wt_checkPoint_lock	Number of checkpoint lock acquisitions in the WiredTiger cache	Item	-	Single node ReplicaSet Sharded cluster
		wt_dhandle_read_lock	The number of read locks acquired for data handles in the WiredTiger cache.	Count	-
		wt_dhandle_write_lock	The number of times a write lock is acquired for a data handle in the WiredTiger cache.	Count	-
		wt_metadata_lock	The number of metadata locks acquired in the WiredTiger cache	Count	-
		wt_schema_lock	The number of schema locks acquired in the WiredTiger cache.	Count	-
		wt_table_read_lock	The number of table read locks acquired in the WiredTiger cache.	Count	-
		wt_table_write_lock	The number of table write locks acquired in the WiredTiger cache.	Count	-
		wt_txn_global_read_lock	The number of times the global read lock is acquired in the WiredTiger cache.	Count	-
		wt_txn_global_write_lock	The number of global write locks acquired in the WiredTiger cache.	Count	-
Thread yielding	MongoDB_WtCache_Thread_Yield	page_acquire_eviction_blocked	Number of times blocked waiting for page eviction	Count	-	Single node ReplicaSet Sharded cluster
		page_acquire_locked_blocked	Number of waits for a locked target page	Times	-
		page_acquire_time_sleeping	Total thread sleep duration when fetching a page	us	-
WiredTigerUsage	MongoDB_WTCacheUsage	wt_cache_updates_usage	WiredTiger update cache utilization	%	The proportion of the maximum cache size in bytes that is allocated for update operations.	Single node ReplicaSet Sharded cluster
Classic multi-planner execution statistics	MongoDB_MultiPlanner_Worker	metrics_query_multiplanner_classicworks	Total number of tasks	Count	The total number of tasks executed by the classic multi-planner.	ReplicaSet Sharded cluster (mongod only)
Logical session cache information	MongoDB_LogicalSession	active_sessions_count	Number of logical sessions in the cache	Item	The total number of logical sessions in the cache since the last refresh.	ReplicaSet sharded cluster

Advanced monitoring

Note

Only standalone, replica set, and sharded cluster instances support Advanced Monitoring.
For information about the specific metrics supported by your instance type, see the console.

Supported instances	Metric	Metric and description	Description	Unit
Standalone instances Replica set instances Sharded cluster instances	CPU usage	cpu_usage	The CPU usage of the instance.	%
	Memory usage	mem_usage	The memory usage of the instance.	%
	Disk space usage	ins_size	Total space used.	Bytes
		data_size	Data disk space used.	Bytes
		log_size	Log disk space used.	Bytes
	Connection usage	conn_usage	The ratio of the current number of connections to the maximum number of connections.	%
	Cursors	open_no_timedout	The number of open cursors that do not have a timeout.	Unit
		pinned_open	The number of cursors that are currently in use.	Unit
		open_total	The total number of open cursors.	Item
		closed_by_timeout	The number of cursors closed due to a timeout.	Unit
		closed_by_session	The number of cursors closed because a session was closed.	Unit
	Read/write queues	currentQueue_total	The total number of operations waiting for a lock.	Unit
		currentQueue_readers	The number of operations waiting for a read lock.	Unit
		currentQueue_writers	The number of operations waiting for a write lock.	Count
		active_readers	The number of active client connections performing read operations.	Item
		active_writers	The number of active client connections performing write operations.	Item
	Average response time (MongoDB_RT)	avg_RT	The average response time of the instance.	microseconds
		reads_avg_rt	The average response time for read operations.	microseconds
		writes_avg_rt	The average response time for write operations.	microseconds
		commands_avg_rt	The average response time for command operations.	microseconds
		trans_avg_rt	The average response time for transaction operations.	microseconds
	WiredTiger request queues	write_concurrent_trans_out	The number of concurrent write requests.	Count
		read_concurrent_trans_out	The number of concurrent read requests.	Unit
		write_concurrent_trans_available	The number of available concurrent write requests.	Unit
		read_concurrent_trans_available	The number of available concurrent read requests.	Unit
	I/O latency	iocheck_cost	The response performance of the current I/O. Note Supported only for standalone instances and replica set instances that run MongoDB 4.0 or earlier.	ms
	WiredTiger cache usage	wt_cache_usage	The WiredTiger cache usage.	%
	WiredTiger cache usage	wt_cache_dirty_usage	The WiredTiger dirty cache usage.	%
	Number of documents affected	deletedDocuments	The number of documents deleted.	Unit
		insertedDocuments	The number of documents inserted.	Unit
		returnDocuments	The number of documents returned.	Count
		updatedDocuments	The number of documents updated.	Item
	Operation details	scanAndOrder	The number of requests that cannot use an index for sorting.	Item
		writeConflicts	The number of write conflicts.	Unit
		exactIDCount	The number of requests that need to obtain matching _id information by broadcasting.	Count
	Number of indexes and documents scanned in queries	scannedKeys	The number of index keys scanned in queries.	Count
	Number of indexes and documents scanned in queries	scannedDocs	The number of documents scanned in queries.	Unit
	TTL	ttlDeletedDocuments	The number of documents deleted due to a TTL index.	Item
	TTL	ttlPasses	The number of times the background TTL thread performed deletions.	Item
	Lock acquisitions	wiredTiger_schema_lock_delta	The number of times a schema lock was acquired.	Item
		wiredTiger_metadata_lock_delta	The number of times a metadata lock was acquired.	Units
		wiredTiger_table_read_lock_delta	The number of times a table read lock was acquired.	Unit
		wiredTiger_table_write_lock_delta	The number of times a table write lock was acquired.	Item
		wiredTiger_txn_global_read_lock_delta	The number of times a global read lock for transactions was acquired.	Unit
		wiredTiger_txn_global_write_lock_delta	The number of times a global write lock for transactions was acquired.	Unit
	MBPS	read_io_bandwidth_mbps	The disk read throughput.	MB/s
		write_io_bandwidth_mbps	The disk write throughput.	MB/s
		io_bandwidth_mbps	The total disk throughput.	MB/s
	Number of transaction operations	trans_totalPrepared_ps	The number of prepared transactions.	Unit
		trans_totalPreparedThenCommited_ps	The number of prepared transactions that were successfully committed.	Count
		trans_totalPreparedThenAborted_ps	The number of prepared transactions that were successfully rolled back.	Unit
		trans_totalStarted_ps	The number of started transactions.	Item
		trans_totalCommited_ps	The number of successfully committed transactions.	Unit
		trans_totalAborted_ps	The number of successfully rolled back transactions.	Unit
	MBPS usage	total_mbps_usage	The disk read/write bandwidth usage. Note Supported only for instances that use disks. For sharded cluster instances, this metric is valid only for the shard component.	%
	WiredTiger	bytes_read_into_cache	The amount of data read into the cache.	Bytes
		bytes_written_from_cache	The amount of data written to the disk from the cache.	Bytes
		maximum_bytes_configured	The maximum configured disk size.	Bytes
	Disk space usage	disk_usage	The ratio of the total space used to the maximum available space.	%
	Operation QPS	insert	You can insert an operand.	Unit
		query	The number of query operations.	Unit
		update	The number of update operations.	Count
		delete	The number of delete operations.	Item
		getmore	The number of read operations.	Count
command		The number of protocol command operations.	Count
Connections	current_conn	The total number of current connections to the instance.	Item
Connections	active_conn	The number of active connections to the instance.	Unit
Network traffic	bytes_in	Inbound traffic.	Bytes
Network traffic	bytes_out	Outbound traffic.	Bytes
Replica set instances Sharded cluster instances	IOPS usage	data_iops(iops)	IOPS usage. Note Viewing IOPS usage or utilization is not currently supported for disk-based instances of version 4.2. The data_iops and log_iops metrics from earlier monitoring versions are now merged into data_iops(iops).	counts/s
	IOPS usage rate	iops_usage	The ratio of the IOPS used by the instance to the maximum available IOPS. Note Instances that use disks and run MongoDB 4.2 do not support viewing IOPS usage and IOPS usage rate.	%
	Primary-secondary latency	repl_lag	The data synchronization latency between the primary and secondary nodes of the instance. Note The heartbeat interval between replica set nodes is 2 seconds. Therefore, a repl_lag value between -2 and 2 is normal for replica set instances, shard nodes of sharded cluster instances, and ConfigServer nodes. A negative repl_lag value for a secondary node does not mean that the secondary node is ahead of the primary node. To get the latest replication latency status of a replica set, run rs.printSecondaryReplicationInfo() on the primary node.	s
Sharded cluster instances	Total operation QPS for the shard component of a sharded cluster	insert_primary	The number of insert operations on the primary node.	Unit
		query_primary	The number of query operations on the primary node.	Item
		update_primary	The number of update operations on the primary node.	Count
		delete_primary	The number of delete operations on the primary node.	Unit
		getmore_primary	The number of read operations on the primary node.	Unit
		command_primary	The number of protocol command operations on the primary node.	Unit
		insert_secondary	The number of insert operations on secondary nodes.	Item
		query_secondary	The number of query operations on secondary nodes.	Item
		insert_hidden	The number of insert operations on hidden nodes.	Count
		query_hidden	The number of query operations on hidden nodes.	Unit
		update_hidden	The number of update operations on hidden nodes.	Item
		delete_hidden	The number of delete operations on hidden nodes.	Unit
		getmore_hidden	The number of read operations on hidden nodes.	Unit
		command_hidden	The number of protocol command operations on hidden nodes.	Count
	Total operation QPS for the Mongos component of a sharded cluster	insert	You can insert an operand.	Unit
		query	The number of query operations.	Count
		update	The number of update operations.	Item
		delete	The number of delete operations.	Count
		getmore	The number of read operations.	Item
		command	The number of protocol command operations.	Unit
	moveChunk	donorCount	The number of times the current node acted as the source for a moveChunk or moveRange operation.	Unit
	moveChunk	recipientCount	The number of times the current node acted as the destination shard to receive chunks.	Unit

Performance Trend

Note

For information about the metrics supported by each instance type, see the console.

Supported instances	Metric	Metric and description
Standalone instance Replica set instance Sharded cluster instance	CPU usage	mongodb.cpu_usage: The CPU usage of the instance.
	Memory usage	mongodb.mem_usage: The memory usage of the instance.
	Disk space usage	The performance trend of disk space usage for the instance. This includes: mongodb.detailed_space_usage.ins_size: The total disk space used. mongodb.detailed_space_usage.data_size: The data disk space used. mongodb.detailed_space_usage.log_size: The log disk space used.
	Cursors	The performance trend of the number of cursors for the instance. This includes: mongodb.metrics.cursor.timedOut: The number of cursors that have timed out. mongodb.metrics.cursor.open.total: The number of currently open cursors.
	WiredTiger request queue	The performance trend of the number of read/write requests and the number of available concurrent operations. This includes: mongodb.wiredTiger.write_concurrent_trans_out: The number of concurrent write requests. mongodb.wiredTiger.read_concurrent_trans_out: The number of concurrent read requests. mongodb.wiredTiger.write_concurrent_trans_available: The number of available concurrent write operations. mongodb.wiredTiger.read_concurrent_trans_available: The number of available concurrent read operations. Note This metric is supported only for Standard Edition replica set instances.
	WiredTiger	The performance trend of metrics for the cache layer of the instance's WiredTiger engine. This includes: mongodb.wiredTiger.cache.pages.read.into.cache: The volume of data read into the cache. mongodb.wiredTiger.cache.pages.written.from.cache: The volume of data written from the cache. mongodb.wiredTiger.cache.maximum.bytes.configured: The maximum cache size. Note This metric is supported only for Standard Edition replica set instances.
Standalone instance Replica set instance Sharded cluster instance Serverless instance	Disk usage	mongodb.disk_usage: The disk usage of MongoDB.
	Operation QPS	The performance trend of operations per second (QPS) for the instance. This includes: mongodb.opcounters.insert: The number of insert operations. mongodb.opcounters.query: The number of query operations. mongodb.opcounters.update: The number of update operations. mongodb.opcounters.delete: The number of delete operations. mongodb.opcounters.getmore: The number of getMore operations. mongodb.opcounters.command: The number of command operations.
	Connections	mongodb.connections.current: The total number of current connections to the instance.
	Network traffic	The performance trend of network traffic for the instance. This includes: mongodb.network.bytesIn: The inbound traffic. mongodb.network.bytesOut: The outbound traffic. mongodb.network.numRequests: The number of requests processed.
Replica set instance Sharded cluster instance	IOPS usage	The performance trend of input/output operations per second (IOPS) usage. This includes: mongodb.iops.data_iops: The number of read and write operations on the data disk. mongodb.iops.log_iops: The number of read and write operations on the log disk.
Replica set instance Sharded cluster instance	IOPS usage rate	mongodb.iops_usage: The IOPS usage rate. Note IOPS usage and IOPS usage rate are not supported for version 4.2 replica set instances and sharded cluster instances that use cloud disks.
Replica set instance	GlobalLock	The performance trend of the global lock for the instance. This includes: mongodb.globalLock.currentQueue.total: The total length of the global lock queue. mongodb.globalLock.currentQueue.writers: The total length of the global lock write queue. mongodb.globalLock.currentQueue.readers: The total length of the global lock read queue.