This topic describes parameters available in MongoDB 4.2 up to when this topic is updated.
Replica set instance
Parameter | Force restart | Default value | Value range | Minor engine version | Description | Documentation. |
net.compression.compressors | Yes | snappy,zstd,zlib | [snappy|zlib|zstd|snappy,zstd,zlib|disabled] | Unlimited | The network compression algorithm used by mongod or mongos. If you specify multiple network compression algorithms, the priorities of the algorithms are in descending order. | |
net.serviceExecutor | Yes | synchronous | [synchronous|adaptive] | Unlimited | The thread and execution model used by mongod or mongos. | |
operationProfiling.mode | Yes | off | [off|slowOp|all] | Unlimited | The level of the operation profiled by the query profiler. Note If this parameter is enabled, instance performance is degraded. Proceed with caution when you want to enable this parameter in the production environment. | |
operationProfiling.slowOpThresholdMs | No | 100 | [0-65536] | Unlimited | The slow operation time threshold. Slow operations refer to operations that run for a longer period of time than this threshold. Unit: milliseconds. | |
replication.enableMajorityReadConcern | Yes | true | [true|false] | Unlimited | Specifies whether to enable the majority read concern feature. | |
replication.oplogGlobalIdEnabled | Yes | false | [true|false] | Unlimited | Specifies whether to enable the global ID (GID) to accelerate two-way synchronization performed by Data Transmission Service (DTS) or mongoShake. | Self-developed parameter |
replication.oplogSizeMB | No | 10% | [1024-1073741824] | Unlimited | The maximum size of the oplog. Unit: MB. The default value is capped at 10% of the disk size. | |
rsconf.writeConcernMajorityJournalDefault | No | true | [true|false] | Unlimited | Specifies whether to persist the journal when the write concern is set to majority. | |
setParameter.cursorTimeoutMillis | No | 600000 | [1-2147483647] | Unlimited | The expiration threshold of the idle cursor. Unit: milliseconds. If the idle time of a cursor exceeds this threshold, ApsaraDB for MongoDB deletes the cursor. In this case, if you attempt to access the cursor again, the system returns the "cursor not found" error message. | |
setParameter.flowControlTargetLagSeconds | No | 10 | [1-600] | Unlimited | The threshold for triggering the flowControl mechanism. Unit: seconds. The flowControl mechanism ensures that a majority of data is committed within the specified threshold. | |
setParameter.internalQueryExecMaxBlockingSortBytes | No | 33554432 | [33554432-268435456] | Unlimited | The maximum available memory during the sorting phase. Unit: bytes. The default value is equivalent to 32 MB. | To be released |
setParameter.maxTransactionLockRequestTimeoutMillis | No | 5 | [0-60] | Unlimited | The timeout period for the transaction to wait to acquire locks required by the operations in the transaction. Unit: milliseconds. | |
setParameter.replWriterThreadCount | Yes | 16 | [1-256] | Unlimited | The maximum number of threads used to perform replication operations in parallel when synchronizing between primary and secondary instances. The maximum number of threads used is capped at twice the number of CPU cores. | |
setParameter.tcmallocAggressiveMemoryDecommit | No | 0 | [0|1] | Unlimited | Specifies whether to enable the aggressive memory strategy of TCMalloc. The default value 0 indicates that the strategy is disabled. | |
setParameter.tcmallocReleaseRate | No | 1 | [1-10] | Unlimited | The rate at which TCMalloc releases memory to the operating system. A larger value indicates a faster memory release. | |
setParameter.transactionLifetimeLimitSeconds | No | 60 | [1-300] | Unlimited | The total timeout of the transaction, which indicates the lifecycle of the transaction. Unit: seconds. A transaction whose execution time exceeds this threshold is aborted to relieve the pressure on the WiredTiger cache. | |
storage.wiredTiger.collectionConfig.blockCompressor | Yes | snappy | [snappy|zlib|zstd|none] | Unlimited | The default storage compression algorithm of collection data. If you change the default algorithm, only all new collections use the specified new algorithm. To use another storage compression algorithm for another collection, run the | |
rsconf.chainingAllowed | No | true | [true|false] | Unlimited | Specifies whether to allow chained replication for the replica set instance. For example, data is replicated from the primary node to a secondary node and then to a hidden node or from the primary node to a hidden node and then to a secondary node. |
Sharded cluster instance (parameters available only for shard)
Parameter | Force restart | Default value | Value range | Minor engine version | Description | Documentation. |
net.compression.compressors | Yes | snappy,zstd,zlib | [snappy|zlib|zstd|snappy,zstd,zlib|disabled] | Unlimited | The network compression algorithm used by mongod or mongos. If you specify multiple network compression algorithms, the priorities of the algorithms are in descending order. | |
net.serviceExecutor | Yes | synchronous | [synchronous|adaptive] | Unlimited | The thread and execution model used by mongod or mongos. | |
operationProfiling.mode | Yes | off | [off|slowOp|all] | Unlimited | The level of the operation profiled by the query profiler. Note If this parameter is enabled, instance performance is degraded. Proceed with caution when you want to enable this parameter in the production environment. | |
operationProfiling.slowOpThresholdMs | No | 100 | [0-65536] | Unlimited | The slow operation time threshold. Slow operations refer to operations that run for a longer period of time than this threshold. Unit: milliseconds. | |
replication.enableMajorityReadConcern | Yes | true | [true|false] | Unlimited | Specifies whether to enable the majority read concern feature. | |
replication.oplogGlobalIdEnabled | Yes | false | [true|false] | Unlimited | Specifies whether to enable the GID to accelerate two-way synchronization performed by DTS or mongoShake. | Self-developed parameter |
replication.oplogSizeMB | No | 10% | [1024-1073741824] | Unlimited | The maximum size of the oplog. Unit: MB. The default value is capped at 10% of the disk size. | |
rsconf.writeConcernMajorityJournalDefault | No | true | [true|false] | Unlimited | Specifies whether to persist the journal when the write concern is set to majority. | |
setParameter.cursorTimeoutMillis | No | 600000 | [1-2147483647] | Unlimited | The expiration threshold of the idle cursor. Unit: milliseconds. If the idle time of a cursor exceeds this threshold, ApsaraDB for MongoDB deletes the cursor. In this case, if you attempt to access the cursor again, the system returns the "cursor not found" error message. | |
setParameter.flowControlTargetLagSeconds | No | 10 | [1-600] | Unlimited | The threshold for triggering the flowControl mechanism. Unit: seconds. The flowControl mechanism ensures that a majority of data is committed within the specified threshold. | |
setParameter.internalQueryExecMaxBlockingSortBytes | No | 33554432 | [33554432-268435456] | Unlimited | The maximum available memory during the sorting phase. Unit: bytes. The default value is equivalent to 32 MB. | To be released |
setParameter.maxTransactionLockRequestTimeoutMillis | No | 5 | [0-60] | Unlimited | The timeout period for the transaction to wait to acquire locks required by the operations in the transaction. Unit: milliseconds. | |
setParameter.replWriterThreadCount | Yes | 16 | [1-256] | Unlimited | The maximum number of threads used to perform replication operations in parallel when synchronizing between primary and secondary instances. The maximum number of threads used is capped at twice the number of CPU cores. | |
setParameter.tcmallocAggressiveMemoryDecommit | No | 0 | [0|1] | Unlimited | Specifies whether to enable the aggressive memory strategy of TCMalloc. The default value 0 indicates that the strategy is disabled. | |
setParameter.tcmallocReleaseRate | No | 1 | [1-10] | Unlimited | The rate at which TCMalloc releases memory to the operating system. A larger value indicates a faster memory release. | |
setParameter.transactionLifetimeLimitSeconds | No | 60 | [1-300] | Unlimited | The total timeout of the transaction, which indicates the lifecycle of the transaction. Unit: seconds. A transaction whose execution time exceeds this threshold is aborted to relieve the pressure on the WiredTiger cache. | |
storage.wiredTiger.collectionConfig.blockCompressor | Yes | snappy | [snappy|zlib|zstd|none] | Unlimited | The default storage compression algorithm of collection data. If you change the default algorithm, only all new collections use the specified new algorithm. To use another storage compression algorithm for another collection, run the | |
setParameter.migrateCloneInsertionBatchSize | No | 0 | [0-1000] | Unlimited | The maximum number of documents to insert in a single batch during the cloning stage of the chunk migration process. The default value 0 indicates that batches can contain up to 16 MB of documents. | |
setParameter.rangeDeleterBatchDelayMS | No | 20 | [0-600000] | Unlimited | The interval to wait before the next batch of deletion during the cleanup stage of the chunk migration process. Unit: milliseconds. This parameter affects the | |
setParameter.rangeDeleterBatchSize | No | 0 | [0-1000] | Unlimited | The maximum number of documents in a single batch of asynchronous deletion during the cleanup stage of the chunk migration process. The default value 0 indicates that the system uses an appropriate value. In most cases, the value is 128. | |
rsconf.chainingAllowed | No | true | [true|false] | Unlimited | Specifies whether to allow chained replication for the shard. For example, data is replicated from a primary node to a secondary node and then to a hidden node or from a primary node to a hidden node and then to a secondary node. |
Sharded cluster instance (parameters available only for mongos)
Parameter | Force restart | Default value | Value range | Minor engine version | Description | Documentation. |
net.compression.compressors | Yes | snappy,zstd,zlib | [snappy|zlib|zstd|snappy,zstd,zlib|disabled] | Unlimited | The network compression algorithm used by mongod or mongos. If you specify multiple network compression algorithms, the priorities of the algorithms are in descending order. | |
net.serviceExecutor | Yes | synchronous | [synchronous|adaptive] | Unlimited | The thread and execution model used by mongod or mongos. | |
operationProfiling.slowOpThresholdMs | No | 100 | [0-65536] | Unlimited | The slow operation time threshold. Slow operations refer to operations that run for a longer period of time than this threshold. Unit: milliseconds. | |
setParameter.cursorTimeoutMillis | No | 600000 | [1-2147483647] | Unlimited | The expiration threshold of the idle cursor. Unit: milliseconds. If the idle time of a cursor exceeds this threshold, ApsaraDB for MongoDB deletes the cursor. In this case, if you attempt to access the cursor again, the system returns the "cursor not found" error message. | |
setParameter.ShardingTaskExecutorPoolHostTimeoutMS | No | 300000 | [60000-3600000] | Unlimited | The timeout period for mongos to drop all connections in the TaskExecutor connection pool in the host. | |
setParameter.ShardingTaskExecutorPoolMaxConnecting | No | 2 | [1-32] | Unlimited | The maximum number of connections that can be established in the TaskExecutor connection pool during connection initialization. This parameter specifies the speed of connection establishment between mongos and mongod. | |
setParameter.ShardingTaskExecutorPoolMaxSize | No | 32767 | [1-32767] | Unlimited | The maximum number of connections in each TaskExecutor connection pool. | |
setParameter.ShardingTaskExecutorPoolMinSize | No | 1 | [1-256] | Unlimited | The minimum number of connections in each TaskExecutor connection pool. | |
setParameter.ShardingTaskExecutorPoolRefreshRequirementMS | No | 60000 | [30000-3600000] | Unlimited | The interval at which a mongos component performs heartbeat detection on a resting connection in the TaskExecutor connection pool. | |
setParameter.ShardingTaskExecutorPoolRefreshTimeoutMS | No | 20000 | [5000-600000] | Unlimited | The timeout period for mongos to wait for a heartbeat. | |
setParameter.taskExecutorPoolSize | No | 1 | [1-32] | Unlimited | The number of TaskExecutor connection pools on mongos. You cannot change this parameter value in Linux. | |
setParameter.tcmallocAggressiveMemoryDecommit | No | 0 | [0|1] | Unlimited | Specifies whether to enable the aggressive memory strategy of TCMalloc. The default value 0 indicates that the strategy is disabled. | |
setParameter.tcmallocReleaseRate | No | 1 | [1-10] | Unlimited | The rate at which TCMalloc releases memory to the operating system. A larger value indicates a faster memory release. |
Sharded cluster instance (parameters available only for ConfigServer)
Parameter | Force restart | Default value | Value range | Minor engine version | Description | Documentation. |
net.compression.compressors | Yes | snappy,zstd,zlib | [snappy|zlib|zstd|snappy,zstd,zlib|disabled] | Unlimited | The network compression algorithm used by mongod or mongos. If you specify multiple network compression algorithms, the priorities of the algorithms are in descending order. | |
operationProfiling.mode | Yes | off | [off|slowOp|all] | Unlimited | The level of the operation profiled by the query profiler. Note If this parameter is enabled, instance performance is degraded. Proceed with caution when you want to enable this parameter in the production environment. | |
operationProfiling.slowOpThresholdMs | No | 100 | [0-65536] | Unlimited | The slow operation time threshold. Slow operations refer to operations that run for a longer period of time than this threshold. Unit: milliseconds. | |
replication.oplogGlobalIdEnabled | Yes | false | [true|false] | Unlimited | Specifies whether to enable the GID to accelerate two-way synchronization performed by DTS or mongoShake. | Self-developed parameter |
setParameter.cursorTimeoutMillis | No | 600000 | [1-2147483647] | Unlimited | The expiration threshold of the idle cursor. Unit: milliseconds. If the idle time of a cursor exceeds this threshold, ApsaraDB for MongoDB deletes the cursor. In this case, if you attempt to access the cursor again, the system returns the "cursor not found" error message. | |
storage.wiredTiger.collectionConfig.blockCompressor | Yes | snappy | [snappy|zlib|zstd|none] | Unlimited | The default storage compression algorithm of collection data. If you change the default algorithm, only all new collections use the specified new algorithm. To use another storage compression algorithm for another collection, run the |