Client Settings

  • reference
    Client settings.

    I/O Options

    This section provides basic settings that will come in handy while configuring network related operations.

    Name: DNS SRV Timeout

    Connection String Option: enable_dns_srv

    Default: true

    Gets the bootstrap node list from a DNS SRV record. See the Connection Management section for more information on how to use it properly.

    Name: Mutation Tokens Enabled

    Connection String Options: enable_mutation_tokens

    Default: true

    Mutation tokens allow enhanced durability requirements as well as advanced SQL++ (formerly N1QL) querying capabilities. Set this to false if you do not require these features and wish to avoid the associated overhead.

    Name: Socket Keepalive

    Connection String Option: enable_tcp_keep_alive

    Default: true

    If enabled, the client periodically sends a TCP keepalive to the server to prevent firewalls and other network equipment from dropping idle TCP connections.

    Name: Socket Keepalive Interval

    Connection String Option: tcp_keep_alive_interval

    Default: 60000ms

    The idle time after which a TCP keepalive gets fired. (This setting has no effect if enable_tcp_keep_alive is false.)

    This setting only propagates to the OS on Linux when the epoll transport is used. On all other platforms, the OS-configured time is used (and you need to tune it there if you want to override the default interval).
    Name: Config Poll Interval

    Cluster Option: config_poll_interval

    Default: 2500ms

    The interval at which the client fetches cluster topology information in order to proactively detect changes.

    Timeout Options

    The default timeout values are suitable for most environments, and should be adjusted only after profiling the expected latencies in your deployment environment. If you get a timeout exception, it may be a symptom of another issue; increasing the timeout duration is sometimes not the best long-term solution.

    Most timeouts can be overridden on a per-operation basis (for example, by passing a custom options block to a "get" or "query" method). The values set here are used as the defaults when no per-operation timeout is specified.

    The cluster-wide timeouts might be changed using connection string in milliseconds.


    Timeout Options Reference

    Name: Key-Value Timeout

    Connection String Option: kv_timeout

    Default: 2500ms but see TIP, below

    The Key/Value default timeout is used on operations which are performed on a specific key if not overridden by a custom timeout. This includes all commands like get, lookup_in and all mutation commands, but does not include operations that are performed with enhanced durability requirements.

    Durable Write operations have their own timeout setting, kv_durable_timeout, see below.
    Name: Key-Value Durable Operation Timeout

    Connection String Option: kv_durable_timeout

    Default: 10000ms

    Key/Value operations with enhanced durability requirements may take longer to complete, so they have a separate default timeout.

    Do not set this above 65s, which is the maximum possible SyncWrite timeout on the Server side.

    The kv_durable_timeout property is not part of the stable API and may change or be removed at any time.
    Name: View Timeout

    Connection String Option: view_timeout

    Default: 75000ms

    The View timeout is used on view operations if not overridden by a custom timeout. Note that it is set to such a high timeout compared to key/value since it can affect hundreds or thousands of rows. Also, if there is a node failure during the request the internal cluster timeout is set to 60 seconds.

    Name: Query Timeout

    Connection String Option: query_timeout

    Default: 75000ms

    The Query timeout is used on all SQL++ query operations if not overridden by a custom timeout. Note that it is set to such a high timeout compared to key/value since it can affect hundreds or thousands of rows.

    Name: Search Timeout

    Connection String Option: search_timeout

    Default: 75000ms

    The Search timeout is used on all FTS operations if not overridden by a custom timeout. Note that it is set to such a high timeout compared to key/value since it can affect hundreds or thousands of rows.

    Name: Analytics Timeout

    Connection String Option: analytics_timeout

    Default: 75000ms

    The Analytics timeout is used on all Analytics query operations if not overridden by a custom timeout. Note that it is set to such a high timeout compared to key/value since it can affect hundreds or thousands of rows.

    Name: Management Timeout

    Connection String Option: management_timeout

    Default: 75000s

    The management timeout is used on all cluster management APIs (BucketManager, UserManager, CollectionManager, QueryIndexManager, etc.) if not overridden by a custom timeout. The default is quite high because some operations (such as flushing a bucket, for example) might take a long time.

    General Options

    Name: Unordered Execution

    Cluster Option: enable_unordered_execution

    Default: true

    From Couchbase 7.0, Out-of-Order execution allows the server to concurrently handle multiple requests on the same connection, potentially improving performance for durable writes and multi-document ACID transactions. This means that tuning the number of connections (KV endpoints) is no longer necessary as a workaround where data not available in the cache is causing timeouts.

    This is set to true by default. Note, changing the setting will only affect Server versions 7.0 onwards.

    Commonly Used Options

    The defaults above have been carefully considered and in general it is not recommended to make changes without expert guidance or careful testing of the change. Some options may be commonly used together in certain envionments or to achieve certain effects.

    Constrained Network Environments

    Though wide area network (WAN) connections are not directly supported, some development and non-critical operations activities across a WAN are convenient. Most likely for connecting to Couchbase Capella, or Server running in your own cloud account, whilst developing from a laptop or other machine not located in the same data center. These settings are some you may want to consider adjusting:

    • Connect Timeout to 30s

    • Key-Value Timeout to 5s

    • Config Poll Interval to 10s

    • Circuit Breaker ErrorThresholdPercentage to 75

    As of SDK API 3.4 you can also use a Configuration Profile, which allows you to quickly configure your environment for common use-cases. See the Configuration Profiles section for more details.

    Configuration Profiles

    Configuration Profiles provide predefined client settings that allow you to quickly configure an environment for common use-cases. When using a configuration profile, the current client settings are overridden with the values provided in the profile. Any property that is not specified in the profile is left unchanged.

    The Configuration Profiles feature is currently a Volatile API and may be subject to change.

    WAN Development

    Cluster Option: apply_profile("wan_development")

    A wan_development configuration profile can be used to modify client settings for development or high-latency environments. This profile changes the default timeouts.

    Table 1. Profile Settings
    Setting Value