Yandex StoreDoc settings

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Updated at October 27, 2026

How settings depend on the host class
Cluster-level DBMS settings

When creating or editing a Yandex StoreDoc cluster, you can specify settings that pertain to Yandex StoreDoc.

The label next to the setting name helps determine which interface is used to set the value of this setting: the management console, CLI, API, or API.

The name of a setting depends on the interface you use. For example, Max incoming connections in the management console is the same as:

max_incoming_connections in gRPC or the CLI
maxIncomingConnections in the REST API

In a sharded cluster, some settings are only available to certain host roles.

How settings depend on the host class

Some Yandex StoreDoc setting values may be automatically changed as you edit the host class:

If no values are set or the values are not compatible with the new class, the defaults for this class will apply.
If the settings you specify manually are compatible with the new class, they will not be changed.

The settings that depend on the host class are:

Cluster-level DBMS settings

Storage All interfaces
- Journal → Commit interval
  
  The interval in milliseconds between the saves of Yandex StoreDoc journal data to the disk.
  
  The minimum value is 1, the maximum is 500, and the default is 300.
  
  This setting is not available for hosts with the MONGOS and MONGOCFG roles in a sharded cluster.
- Wired tiger
  
  Settings for the storage engine:
  - Collection config → Block compressor
    
    Data compression option. The value set here only applies to new collections. You can also redefine it for individual collections and indexes.
    - none: Compression disabled.
    - snappy: Use the snappy library for data compression. If you select this setting, data compression/decompression will be, in most cases, faster than if using the zlib library; however, the resulting file size will be 20% to 100% larger.
    - zlib: Use the zlib library for data compression. This method is slower than snappy but, in most cases, it achieves better data compression.
    This setting is not available for hosts with the MONGOS and MONGOCFG roles in a sharded cluster.
  - Engine config → Cache size gb
    
    Maximum size of the internal cache used for data storage (in GB). This setting does not affect the amount of RAM used to create an index.
    
    The default value depends on the RAM of the selected host class:
    - <host_RAM_amount> ≤ 2 GB: 0.5.
    - 2 GB < <host_RAM_amount> ≤ 4 GB: 1.
    - <host_RAM_amount> > 4 GB: Calculated using this formula: (RAM − 1) ÷ 2.
    The Cache size setting takes priority over the Cache size gb setting. If both settings are specified, the Cache size value is taken.
    
    The Cache size gb setting is not available for hosts with the MONGOS role in a sharded cluster.
  - Engine config → Cache size
    
    Maximum size of the internal cache used for data storage, as a percentage.
    
    The minimum value depends on the RAM of the selected host class. The internal cache size must be not less than 0.25 GB, equivalent.
    
    The maximum value is 90.
    
    This setting is unavailable for hosts with the MONGOS role in a sharded cluster.
  - Index config → Prefix compression
    
    Enables or disables prefix compression for indexes. Changing the parameter only affects new indexes, not the existing ones.
    
    Default value: true (prefix compression enabled).
    
    This setting is not available for hosts with the MONGOS and MONGOCFG roles in a sharded cluster.
Operation profiling All interfaces

DBMS profiler settings. The profiler collects query data and uses it to generate a query optimization strategy.
- Mode
  
  DBMS profiler mode:
  - off: Profiling disabled.
  - slowOp (default): Only collects information about slow operations (that take longer than the threshold value specified in the Slow op threshold setting).
  - all: Collects information about all queries in progress.
  This setting is unavailable for hosts with the MONGOS role in a sharded cluster.
- Slow op sample rate
  
  The number of slow operations to profile or log. If enabled, this parameter affects diagnostic logging and the profiler.
  
  The minimum value is 0, the maximum is 1, and the default is 1.
  
  This setting is unavailable for hosts with the MONGOS role in a sharded cluster.
- Slow op threshold
  
  Sets the operation execution time (in milliseconds). If exceeded, the operation is considered slow.
  
  Minimum value: 0; maximum value: 36000000 (10 hours); default: 300.
  
  This setting is unavailable for hosts with the MONGOS role in a sharded cluster.
Net All interfaces

Networking settings.
- Max incoming connections
  
  Maximum number of inbound connections.
  
  The minimum value is 10. The maximum value depends on the selected host class and is equal to the host's RAM volume in MB, with a maximum of 16384. The default value is 1024.
  
  For more information, see Limits on the number of connections.
- Compression → Compressors
  
  Lists the compression methods that a host with the MONGOD or MONGOS role can use to compress network messages. The order of the listing is important.
  
  The disabled value disables compression. The default value is snappy,zstd,zlib.
Audit Log All interfaces

audit system log settings.
- Filter
  
  This setting decides which audit events to log. An input parameter is any audit message field in JSON string format.
  
  For example, to log only audit events related to users named example-user and new-user, specify the following:
```
{ "user": { $in: [ "example-user", "new-user" ] } }
```
Note

You can also configure exporting cluster audit logs to a trail using Yandex Audit Trails.
Set parameter
- Audit authorization success All interfaces
  
  Determines whether the audit system will log successful authorization operations (authCheck). If set to true, the system will log both authorized and unauthorized operations.
  
  The default value is false (only failed authorization attempts are logged).
- Enable flow control All interfaces
  
  Decides whether or not to control the rate of primary host's write operations. Enabling this parameter ensures that the majority committed metric for replica hosts will not exceed the set Flow control target lag seconds value.
  
  The default value is false (flow control is disabled).
  
  This setting is unavailable for hosts with the MONGOS role in a sharded cluster.
- Flow control target lag seconds All interfaces
  
  With the Enable flow control setting enabled, the majority of operations will be implemented within the time limit (in seconds) specified in the Flow control target lag seconds setting.
  
  The default value is 10.
  
  This setting is available for hosts with the MONGOD role only.
- Flow control warn threshold seconds All interfaces
  
  With the Enable flow control setting enabled, the flow control monitors the majority commit point. If this point does not change within the time period (in seconds) specified in the Flow control warn threshold seconds setting, a warning is logged.
  
  The default value is 10. The 0 value disables warnings.
  
  This setting is available for hosts with the MONGOD role only.
- Migrate clone insertion batch delay ms All interfaces
  
  Timeout (in ms) between insertion batches at the cloning stage when migrating chunks across shards.
  
  The default value is 0 (no delays between insertion batches).
  
  This setting is available for hosts with the MONGOD role only.
- Migrate clone insertion batch size All interfaces
  
  Maximum number of documents to insert in one batch at the cloning stage when migrating chunks across shards.
  
  The default value is 0 (the number is unlimited).
  
  This setting is available for hosts with the MONGOD role only.
- Min snapshot history window in seconds All interfaces
  
  Time, in seconds, for snapshot history to be retained.
  
  Possible values: from zero up. Default value: 60. Increasing this setting value increases disk usage.
  
  This setting is available for hosts with the MONGOD role only.
- Orphan cleanup delay secs All interfaces
  
  Minimum delay, in seconds, before deleting a migrated fragment from the source shard.
  
  The default value is 900 (15 minutes).
  
  This setting is available for hosts with the MONGOD role only.
- Persisted chunk cache update max batch size All interfaces
  
  Maximum number of documents in a batch when updating data in the persisted chunk cache.
  
  The default value is 1000.
  
  This setting is available for hosts with the MONGOD role only.
- Range deleter batch delay ms All interfaces
  
  Delay, in ms, before the next deletion batch at the cleanup stage when migrating chunks across shards (or when running the cleanupOrphaned command).
  
  The default value is 20.
  
  This setting is available for hosts with the MONGOD role only.
- Range deleter batch size All interfaces
  
  Maximum number of documents per batch to delete at the cleanup stage when migrating chunks across shards (or when running the cleanupOrphaned command).
  
  The default value is 2147483647.
  
  This setting is available for hosts with the MONGOD role only.
- Mirror reads All interfaces
  
  Data mirror reads settings.
  - Sampling rate
    
    The master host's sampling rate of mirroring read operations to available replica hosts.
    
    The value must be in the range from 0.0 (mirroring is disabled) to 1.0 (the master host duplicates all operations that support mirroring to each available replica host).
    
    The default value is 0.01.
    
    This setting is available for hosts with the MONGOD role only.
  - Max time ms
    
    Maximum time, in ms, for mirror reads.
    
    The default value is 1000.
    
    This setting is available for hosts with the MONGOD role only.
- Read hedging mode All interfaces
  
  Shows if the MONGOS hosts support hedging for reads with the enabled read hedging option.
  
  The default value is on.
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool max size All interfaces
  
  Maximum number of outbound connections each TaskExecutor connection pool can establish to any MONGOD host.
  
  The default value is 32767.
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool max connecting All interfaces
  
  Maximum number of concurrently initiated connections (including pending connections that are being installed or updated) to a MONGOD host each TaskExecutor connection pool can support.
  
  The default value is 2.
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool min size All interfaces
  
  Minimum number of outbound connections each TaskExecutor connection pool must establish to any MONGOD host.
  
  The default value is 1.
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool replica set matching All interfaces
  
  Policy that sets the minimum size of the MONGOS host's connection pools for each replica set.
  
  The possible values are:
  - automatic (default): Equal to matchPrimaryNode.
  - matchPrimaryNode: The minimum size of the MONGOS host's connection pools for each replica host equals its master host connection pool.
  - matchBusiestNode: The minimum size of the MONGOS host's connection pools for each replica host equals the highest number of active connections to the master host and each replica host.
  - disabled: The minimum size of the MONGOS host's connection pools for each replica host equals the ShardingTaskExecutorPoolMinSize setting value.
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool host timeout ms All interfaces
  
  The maximum time period, in ms, the MONGOS host waits for connection to the host until it terminates all connections to that host.
  
  The default value is 300000 (five minutes).
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool refresh requirement ms All interfaces
  
  The maximum time period, in ms, the MONGOS host waits before checking the state of an inactive connection in the pool.
  
  The default value is 60000 (one minute).
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool refresh timeout ms All interfaces
  
  The maximum time period, in ms, the MONGOS host waits for connection to be confirmed.
  
  The default value is 20000 (20 seconds).
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Warm min connections in sharding task executor pool on startup All interfaces
  
  If this setting is enabled, MONGOS attempts to establish the minimum number of network connections to each host before starting to accept client connections.
  
  The default value is true.
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Warm min connections in sharding task executor pool on startup wait ms All interfaces
  
  Sets the time period, in ms, for the MONGOS host to wait for establishing a connection to each host. This setting only works if the Warm min connections in sharding task executor pool on startup setting is enabled.
  
  The default value is 2000 (two seconds).
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool max size for config servers All interfaces
  
  The maximum number of outbound connections each TaskExecutor connection pool can establish to any MONGOCFG host. This setting overrides the Sharding task executor pool max size setting value when applied to MONGOCFG hosts.
  
  The default value is -1 (the Sharding task executor pool max size setting value is used).
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
- Sharding task executor pool min size for config servers All interfaces
  
  The minimum number of outbound connections each TaskExecutor connection pool can establish to any MONGOCFG host. This setting overrides the Sharding task executor pool min size setting value when applied to MONGOCFG hosts.
  
  The default value is -1 (the Sharding task executor pool min size setting value is used).
  
  This setting is only available for hosts with the MONGOS role in a sharded cluster.
Oplog All interfaces

Oplog (log of all operations that change data in a database) settings.
- Max size percent
  
  Maximum oplog size as a percentage of the disk size.
  
  The default value is as follows:
  - For MONGOD hosts: 5.
  - For MONGOCFG hosts: 0.
  The minimum acceptable oplog size in MB is 990. If the percentage of the disk size is less than 990 MB, the oplog size is considered to be 990 MB. The actual default value for MONGOCFG hosts is always 990 MB.
  
  This setting is unavailable for hosts with the MONGOS role in a sharded cluster.
- Min retention hours
  
  Minimum number of hours to retain oplog records. This setting allows storing old oplog records for the specified time period, even if new records increase the collection size beyond the set limit.
  
  The setting value can be a fractional number. For example, 1.5 means one hour and thirty minutes.
  
  The default value is as follows:
  - For MONGOD hosts: 0 (oplog record retention is disabled).
  - For MONGOCFG hosts: 24.
  This setting is unavailable for hosts with the MONGOS role in a sharded cluster.
Chaining allowed All interfaces

Determines whether chain replication is allowed, whereby replica hosts can replicate data from other replica hosts.

The default value is true.

This setting is unavailable for hosts with the MONGOS role in a sharded cluster.
Chunk Size All interfaces

Size of each chunk, in MB.

The maximum value is 1024; the default value is 128.

This setting is only available for hosts with the MONGOS role in a sharded cluster.

Yandex StoreDoc settings

How settings depend on the host classHow settings depend on the host class

Cluster-level DBMS settingsCluster-level DBMS settings

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How settings depend on the host class

Cluster-level DBMS settings