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ApsaraDB for MongoDB:Parameters available for MongoDB 4.2

Last Updated:Jan 24, 2026

This topic lists the parameters available for ApsaraDB for MongoDB 4.2.

Replica set

Parameter name

Restart required

Default value

Valid values

Minor version range

Description

Official documentation

setParameter.internalDocumentSourceGroupMaxMemoryBytes

No

104857600

[10485760-10485760000]

Unlimited

Limits the maximum memory size that the $group operator can use. Data that exceeds this limit overflows to the disk.

Not disclosed

setParameter.internalQueryMaxPushBytes

No

104857600

[10485760-1048576000]

Unlimited

Limits the maximum memory that the `$push` operator can use.

Not disclosed

setParameter.internalQueryMaxAddToSetBytes

No

104857600

[10485760-1048576000]

Unlimited

Limits the maximum memory that the `$addToSet` operator can use.

Not disclosed

setParameter.internalDocumentSourceCursorBatchSizeBytes

No

4194304

[1048576-104857600]

Unlimited

The maximum amount of data in bytes that a DocumentSourceCursor can cache from the underlying PlanExecutor before pipeline processing.

Not disclosed

setparameter.internalQueryCacheSize

No

5000

[0-5000]

Unlimited

Limits the maximum number of entries in the query plan cache for a collection.

Not disclosed

net.compression.compressors

Yes

snappy,zstd,zlib

[snappy|zlib|zstd|snappy,zstd,zlib|disabled]

Unlimited

The network compression algorithm for a mongod or Mongos instance. If you specify multiple compression algorithms, they are prioritized in descending order.

net.compression.compressors

net.serviceExecutor

Yes

synchronous

[synchronous|adaptive]

Unlimited

Determines the threading and execution model used by a mongod or Mongos instance.

net.serviceExecutor

operationProfiling.mode

Yes

off

[off|slowOp|all]

Unlimited

Specifies the level for the query analysis profiler.

Note

Enabling this parameter degrades instance performance. Use with caution in a production environment.

operationProfiling.mode

operationProfiling.slowOpThresholdMs

No

100

[0-65536]

Unlimited

The threshold for slow operations in milliseconds. An operation is considered slow if its runtime exceeds this threshold.

operationProfiling.slowOpThresholdMs

replication.enableMajorityReadConcern

Yes

true

[true|false]

Unlimited

Specifies whether to enable support for majority read concern.

replication.enableMajorityReadConcern

replication.oplogGlobalIdEnabled

Yes

false

[true|false]

Unlimited

Specifies whether to enable Global ID (GID) to support two-way synchronization using Data Transmission Service (DTS) or mongoShake.

Self-developed parameter

replication.oplogSizeMB

No

10%

[1024-1073741824]

Unlimited

The maximum size of the oplog table in MB. The default value is 10% of the disk size.

replication.oplogSizeMB

rsconf.writeConcernMajorityJournalDefault

No

true

[true|false]

Unlimited

Specifies whether the journal must be persisted to disk when the write concern is set to majority.

replSetGetConfig

setParameter.cursorTimeoutMillis

No

600000

[1-2147483647]

Unlimited

The expiration threshold for idle cursors in milliseconds.

If a cursor is idle for longer than this threshold, MongoDB deletes the cursor. An attempt to access the deleted cursor returns a "cursor not found" error.

cursorTimeoutMillis

setParameter.flowControlTargetLagSeconds

No

10

[1-600]

Unlimited

The threshold in seconds that triggers the flow control mechanism. Flow control ensures that most commit points do not fall too far behind.

flowControlTargetLagSeconds

setParameter.internalQueryExecMaxBlockingSortBytes

No

33554432

[33554432-268435456]

Unlimited

The maximum memory in bytes that a sorting operation can use. The default value is 32 MB.

Not disclosed

setParameter.maxTransactionLockRequestTimeoutMillis

No

5

[0-60]

Unlimited

The timeout in milliseconds for a transaction to wait for a lock.

maxTransactionLockRequestTimeoutMillis

setParameter.replWriterThreadCount

Yes

16

[1-256]

Unlimited

The maximum number of threads for parallel replication during primary-secondary synchronization. The effective maximum number of threads is twice the number of CPU cores for the instance specification.

replWriterThreadCount

setParameter.tcmallocAggressiveMemoryDecommit

No

0

[0|1]

Unlimited

Specifies whether to enable aggressive memory decommitment for tcmalloc. The default value 0 disables this feature.

tcmallocAggressiveMemoryDecommit

setParameter.tcmallocReleaseRate

No

1

[1-10]

Unlimited

The rate at which tcmalloc releases memory to the operating system (OS). A higher value indicates a faster release rate.

tcmallocReleaseRate

setParameter.transactionLifetimeLimitSeconds

No

60

[1-300]

Unlimited

The total timeout for a transaction in seconds. This defines the transaction lifecycle. Transactions that exceed this limit are aborted to reduce pressure on the WiredTiger (WT) cache.

transactionLifetimeLimitSeconds

storage.wiredTiger.collectionConfig.blockCompressor

Yes

snappy

[snappy|zlib|zstd|none]

Unlimited

The storage compression algorithm for collection data. This change applies only to new collections. To use different compression algorithms for different collections, run the createCollection command with the required options.

storage.wiredTiger.collectionConfig.blockCompressor

rsconf.chainingAllowed

No

true

[true|false]

Unlimited

Specifies whether to allow chained replication in the replica set.

For example, data is replicated from the primary node to a secondary node, and then from the secondary node to a hidden node. Alternatively, data is replicated from the primary node to a hidden node, and then from the hidden node to a secondary node.

rsconf.chainingAllowed

Sharded cluster (Shard)

Parameter name

Restart required

Default value

Valid values

Minor version range

Description

Official documentation

setParameter.internalDocumentSourceGroupMaxMemoryBytes

No

104857600

[10485760-10485760000]

Unlimited

Limits the maximum memory size that the $group operator can use. Data that exceeds this limit overflows to the disk.

Not disclosed

setParameter.internalQueryMaxPushBytes

No

104857600

[10485760-1048576000]

Unlimited

Limits the maximum memory that the `$push` operator can use.

Not disclosed

setParameter.internalQueryMaxAddToSetBytes

No

104857600

[10485760-1048576000]

Unlimited

Limits the maximum memory that the `$addToSet` operator can use.

Not disclosed

setParameter.internalDocumentSourceCursorBatchSizeBytes

No

4194304

[1048576-104857600]

Unlimited

The maximum amount of data in bytes that a DocumentSourceCursor can cache from the underlying PlanExecutor before pipeline processing.

Not disclosed

setparameter.internalQueryCacheSize

No

5000

[0-5000]

Unlimited

Limits the maximum number of entries in the query plan cache for a collection.

Not disclosed

net.compression.compressors

Yes

snappy,zstd,zlib

[snappy|zlib|zstd|snappy,zstd,zlib|disabled]

Unlimited

The network compression algorithm for a mongod or Mongos instance. If you specify multiple compression algorithms, they are prioritized in descending order.

net.compression.compressors

net.serviceExecutor

Yes

synchronous

[synchronous|adaptive]

Unlimited

Determines the threading and execution model used by a mongod or Mongos instance.

net.serviceExecutor

operationProfiling.mode

Yes

off

[off|slowOp|all]

Unlimited

Specifies the level for the query analysis profiler.

Note

Enabling this parameter degrades instance performance. Use with caution in a production environment.

operationProfiling.mode

operationProfiling.slowOpThresholdMs

No

100

[0-65536]

Unlimited

The threshold for slow operations in milliseconds. An operation is considered slow if its runtime exceeds this threshold.

operationProfiling.slowOpThresholdMs

replication.enableMajorityReadConcern

Yes

true

[true|false]

Unlimited

Specifies whether to enable support for majority read concern.

replication.enableMajorityReadConcern

replication.oplogGlobalIdEnabled

Yes

false

[true|false]

Unlimited

Specifies whether to enable Global ID (GID) to support two-way synchronization using Data Transmission Service (DTS) or mongoShake.

Self-developed parameter

replication.oplogSizeMB

No

10%

[1024-1073741824]

Unlimited

The maximum size of the oplog table in MB. The default value is 10% of the disk size.

replication.oplogSizeMB

rsconf.writeConcernMajorityJournalDefault

No

true

[true|false]

Unlimited

Specifies whether the journal must be persisted to disk when the write concern is set to majority.

replSetGetConfig

setParameter.cursorTimeoutMillis

No

600000

[1-2147483647]

Unlimited

The expiration threshold for idle cursors in milliseconds.

If a cursor is idle for longer than this threshold, MongoDB deletes the cursor. An attempt to access the deleted cursor returns a "cursor not found" error.

cursorTimeoutMillis

setParameter.flowControlTargetLagSeconds

No

10

[1-600]

Unlimited

The threshold in seconds that triggers the flow control mechanism. Flow control ensures that most commit points do not fall too far behind.

flowControlTargetLagSeconds

setParameter.internalQueryExecMaxBlockingSortBytes

No

33554432

[33554432-268435456]

Unlimited

The maximum memory in bytes that a sorting operation can use. The default value is 32 MB.

Not disclosed

setParameter.maxTransactionLockRequestTimeoutMillis

No

5

[0-60]

Unlimited

The timeout in milliseconds for a transaction to wait for a lock.

maxTransactionLockRequestTimeoutMillis

setParameter.replWriterThreadCount

Yes

16

[1-256]

Unlimited

The maximum number of threads for parallel replication during primary-secondary synchronization. The effective maximum number of threads is twice the number of CPU cores for the instance specification.

replWriterThreadCount

setParameter.tcmallocAggressiveMemoryDecommit

No

0

[0|1]

Unlimited

Specifies whether to enable aggressive memory decommitment for tcmalloc. The default value 0 disables this feature.

tcmallocAggressiveMemoryDecommit

setParameter.tcmallocReleaseRate

No

1

[1-10]

Unlimited

The rate at which tcmalloc releases memory to the operating system (OS). A higher value indicates a faster release rate.

tcmallocReleaseRate

setParameter.transactionLifetimeLimitSeconds

No

60

[1-300]

Unlimited

The total timeout for a transaction in seconds. This defines the transaction lifecycle. Transactions that exceed this limit are aborted to reduce pressure on the WiredTiger (WT) cache.

transactionLifetimeLimitSeconds

storage.wiredTiger.collectionConfig.blockCompressor

Yes

snappy

[snappy|zlib|zstd|none]

Unlimited

The storage compression algorithm for collection data. This change applies only to new collections. To use different compression algorithms for different collections, run the createCollection command with the required options.

storage.wiredTiger.collectionConfig.blockCompressor

setParameter.migrateCloneInsertionBatchSize

No

0

[0-1000]

Unlimited

The maximum number of documents in a single batch during the clone step of a chunk migration. A value of 0 means the batch size is limited only by the 16 MB document size limit.

migrateCloneInsertionBatchSize

setParameter.rangeDeleterBatchDelayMS

No

20

[0-600000]

Unlimited

The delay in milliseconds between batch deletions during the cleanup step of a chunk migration. This also affects the cleanupOrphaned command, which cleans up orphaned documents.

rangeDeleterBatchDelayMS

setParameter.rangeDeleterBatchSize

No

0

[0-1000]

Unlimited

The maximum number of documents in a single batch for asynchronous deletion during the cleanup step of a chunk migration. A value of 0 means an appropriate batch size is automatically selected, which is typically 128.

rangeDeleterBatchSize

rsconf.chainingAllowed

No

true

[true|false]

Unlimited

Specifies whether to allow chained replication in the shard.

For example, data is replicated from the primary node to a secondary node, and then from the secondary node to a hidden node. Alternatively, data is replicated from the primary node to a hidden node, and then from the hidden node to a secondary node.

rsconf.chainingAllowed

Sharded cluster (Mongos)

Parameter name

Restart required

Default value

Valid values

Minor version range

Description

Official documentation

net.compression.compressors

Yes

snappy,zstd,zlib

[snappy|zlib|zstd|snappy,zstd,zlib|disabled]

Unlimited

The network compression algorithm for a mongod or Mongos instance. If you specify multiple compression algorithms, they are prioritized in descending order.

net.compression.compressors

net.serviceExecutor

Yes

synchronous

[synchronous|adaptive]

Unlimited

Determines the threading and execution model used by a mongod or Mongos instance.

net.serviceExecutor

operationProfiling.slowOpThresholdMs

No

100

[0-65536]

Unlimited

The threshold for slow operations in milliseconds. An operation is considered slow if its runtime exceeds this threshold.

operationProfiling.slowOpThresholdMs

setParameter.cursorTimeoutMillis

No

600000

[1-2147483647]

Unlimited

The expiration threshold for idle cursors in milliseconds. If a cursor is idle for longer than this threshold, MongoDB deletes the cursor. An attempt to access the deleted cursor returns a "cursor not found" error.

cursorTimeoutMillis

setParameter.ShardingTaskExecutorPoolHostTimeoutMS

No

300000

[60000-3600000]

Unlimited

The timeout period after which a Mongos instance drops all connections to a host's TaskExecutor connection pool.

ShardingTaskExecutorPoolHostTimeoutMS

setParameter.ShardingTaskExecutorPoolMaxConnecting

No

2

[1-32]

Unlimited

The maximum number of concurrent connections that the TaskExecutor connection pool can initialize. This controls the connection speed from a Mongos instance to a mongod instance.

ShardingTaskExecutorPoolMaxConnecting

setParameter.ShardingTaskExecutorPoolMaxSize

No

32767

[1-32767]

Unlimited

The maximum number of connections in each TaskExecutor connection pool for a sharded cluster instance.

ShardingTaskExecutorPoolMaxSize

setParameter.ShardingTaskExecutorPoolMinSize

No

1

[1-256]

Unlimited

The minimum number of connections in each TaskExecutor connection pool for a sharded cluster instance.

ShardingTaskExecutorPoolMinSize

setParameter.ShardingTaskExecutorPoolRefreshRequirementMS

No

60000

[30000-3600000]

Unlimited

The interval at which a Mongos instance sends heartbeats to check hibernating connections in the TaskExecutor connection pool.

ShardingTaskExecutorPoolRefreshRequirementMS

setParameter.ShardingTaskExecutorPoolRefreshTimeoutMS

No

20000

[5000-600000]

Unlimited

The timeout period for a Mongos instance to wait for a heartbeat response.

ShardingTaskExecutorPoolRefreshTimeoutMS

setParameter.taskExecutorPoolSize

Yes

1

[1-32]

Unlimited

The number of TaskExecutor connection pools on a Mongos instance.

taskExecutorPoolSize

setParameter.tcmallocAggressiveMemoryDecommit

No

0

[0|1]

Unlimited

Specifies whether to enable aggressive memory decommitment for tcmalloc. The default value 0 disables this feature.

tcmallocAggressiveMemoryDecommit

setParameter.tcmallocReleaseRate

No

1

[1-10]

Unlimited

The rate at which tcmalloc releases memory to the operating system (OS). A higher value indicates a faster release rate.

tcmallocReleaseRate

Sharded cluster (ConfigServer)

Parameter name

Restart required

Default value

Valid values

Minor version range

Description

Official documentation

net.compression.compressors

Yes

snappy,zstd,zlib

[snappy|zlib|zstd|snappy,zstd,zlib|disabled]

Unlimited

The network compression algorithm for a mongod or Mongos instance. If you specify multiple compression algorithms, they are prioritized in descending order.

net.compression.compressors

operationProfiling.mode

Yes

off

[off|slowOp|all]

Unlimited

Specifies the level for the query analysis profiler.

Note

Enabling this parameter degrades instance performance. Use with caution in a production environment.

operationProfiling.mode

operationProfiling.slowOpThresholdMs

No

100

[0-65536]

Unlimited

The threshold for slow operations in milliseconds. An operation is considered slow if its runtime exceeds this threshold.

operationProfiling.slowOpThresholdMs

replication.oplogGlobalIdEnabled

Yes

false

[true|false]

Unlimited

Specifies whether to enable Global ID (GID) to support two-way synchronization using Data Transmission Service (DTS) or mongoShake.

Self-developed parameter

setParameter.cursorTimeoutMillis

No

600000

[1-2147483647]

Unlimited

The expiration threshold for idle cursors in milliseconds. If a cursor is idle for longer than this threshold, MongoDB deletes the cursor. An attempt to access the deleted cursor returns a "cursor not found" error.

cursorTimeoutMillis

storage.wiredTiger.collectionConfig.blockCompressor

Yes

snappy

[snappy|zlib|zstd|none]

Unlimited

The storage compression algorithm for collection data. This change applies only to new collections. To use different compression algorithms for different collections, run the createCollection command with the required options.

storage.wiredTiger.collectionConfig.blockCompressor