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Query Settings REST API

  • reference
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    Overview

    The Query Settings REST API is provided by the Query service. This API enables you to view or specify cluster-level Query settings.

    Version information

    Version : 8.0

    Host information

    {scheme}://{host}:{port}

    The URL scheme, host, and port are as follows.

    Component Description

    scheme

    The URL scheme. Use https for secure access.

    Values: http, https
    Example: http

    host

    The host name or IP address of a node running the Query Service.

    Example: localhost

    port

    The Cluster administration REST port. Use 18091 for secure access. Note that the port numbers for this REST API are different to the port numbers used by the other Query REST APIs.

    Values: 8091, 18091
    Example: 8091

    Resources

    This section describes the operations available with this REST API.

    Retrieve CURL Access List
    Retrieve Cluster-Level Query Settings
    Update CURL Access List
    Update Cluster-Level Query Settings

    Retrieve CURL Access List

    GET /settings/querySettings/curlWhitelist

    Description

    Returns the cluster-level CURL access settings only.

    Produces

    • application/json

    Responses

    HTTP Code Description Schema

    200

    An object determining which URLs may be accessed by the CURL() function.

    Access

    Security

    Type Name

    http (basic)

    Default

    Example HTTP Request

    The example below gets the current cluster-level CURL access settings.

    Curl request
    curl -v -u Administrator:password \
http://localhost:8091/settings/querySettings/curlWhitelist

    Example HTTP Response

    Response 200
    {
  "all_access": false,
  "allowed_urls": [],
  "disallowed_urls": []
}

    Retrieve Cluster-Level Query Settings

    GET /settings/querySettings

    Description

    Returns all cluster-level query settings, including the CURL access settings.

    Produces

    • application/json

    Responses

    HTTP Code Description Schema

    200

    An object giving cluster-level query settings.

    Settings

    Security

    Type Name

    http (basic)

    Default

    Example HTTP Request

    The example below gets the current cluster-level query settings.

    Curl request
    curl -v -u Administrator:password \
http://localhost:8091/settings/querySettings

    Example HTTP Response

    Response 200
    {
  "queryTmpSpaceDir": "/opt/couchbase/var/lib/couchbase/tmp",
  "queryTmpSpaceSize": 5120,
  "queryPipelineBatch": 16,
  "queryPipelineCap": 512,
  "queryScanCap": 512,
  "queryTimeout": 0,
  "queryPreparedLimit": 16384,
  "queryCompletedLimit": 4000,
  "queryCompletedThreshold": 1000,
  "queryLogLevel": "info",
  "queryMaxParallelism": 1,
  "queryTxTimeout": "0ms",
  "queryMemoryQuota": 0,
  "queryUseCBO": true,
  "queryCleanupClientAttempts": true,
  "queryCleanupLostAttempts": true,
  "queryCleanupWindow": "60s",
  "queryNumAtrs": 1024,
  "queryNodeQuota": 0,
  "queryUseReplica": "unset",
  "queryNodeQuotaValPercent": 67,
  "queryNumCpus": 0,
  "queryCompletedMaxPlanSize": 262144,
  "queryN1QLFeatCtrl": 76,
  "queryCurlWhitelist": {
    "all_access": false
  }
}

    Update CURL Access List

    POST /settings/querySettings/curlWhitelist

    Description

    Updates the cluster-level CURL access settings only.

    Consumes

    • application/json

    • application/x-www-form-urlencoded

    Produces

    • application/json

    Parameters

    Body Parameter

    Name Description Schema

    Body
    optional

    An object determining which URLs may be accessed by the CURL() function.

    Access

    Responses

    HTTP Code Description Schema

    200

    An object determining which URLs may be accessed by the CURL() function, including the latest changes.

    Access

    400

    Returns an error message if a parameter or value is incorrect.

    Object

    Security

    Type Name

    http (basic)

    Default

    Example HTTP Request

    The example below specifies that https://company1.com is allowed, and https://company2.com is disallowed.

    Curl request
    curl -v -X POST -u Administrator:password \
http://localhost:8091/settings/querySettings/curlWhitelist \
-d '{"all_access": false,
     "allowed_urls": ["https://company1.com"],
     "disallowed_urls": ["https://company2.com"]}'

    Example HTTP Response

    Response 200
    {
  "all_access": false,
  "allowed_urls": [
    "https://company1.com"
  ],
  "disallowed_urls": [
    "https://company2.com"
  ]
}

    Update Cluster-Level Query Settings

    POST /settings/querySettings

    Description

    Updates cluster-level query settings, including the CURL access settings.

    Consumes

    • application/json

    • application/x-www-form-urlencoded

    Produces

    • application/json

    Parameters

    Body Parameter

    Name Description Schema

    Body
    optional

    An object specifying cluster-level query settings.

    Settings

    Responses

    HTTP Code Description Schema

    200

    An object giving cluster-level query settings, including the latest changes.

    Settings

    400

    Returns an error message if a parameter or value is incorrect.

    Object

    Security

    Type Name

    http (basic)

    Default

    Example HTTP Request

    The example below changes the temp file directory to /tmp and the temp file size to 2048 MB.

    Curl request
    curl -v -X POST -u Administrator:password \
http://localhost:8091/settings/querySettings \
-d 'queryTmpSpaceDir=/tmp' \
-d 'queryTmpSpaceSize=2048'

    Example HTTP Response

    Response 200
    {
  "queryTmpSpaceDir": "/tmp",
  "queryTmpSpaceSize": 2048,
  "queryPipelineBatch": 16,
  "queryPipelineCap": 512,
  "queryScanCap": 512,
  "queryTimeout": 0,
  "queryPreparedLimit": 16384,
  "queryCompletedLimit": 4000,
  "queryCompletedThreshold": 1000,
  "queryLogLevel": "info",
  "queryMaxParallelism": 1,
  "queryTxTimeout": "0ms",
  "queryMemoryQuota": 0,
  "queryUseCBO": true,
  "queryCleanupClientAttempts": true,
  "queryCleanupLostAttempts": true,
  "queryCleanupWindow": "60s",
  "queryNumAtrs": 1024,
  "queryNodeQuota": 0,
  "queryUseReplica": "unset",
  "queryNodeQuotaValPercent": 67,
  "queryNumCpus": 0,
  "queryCompletedMaxPlanSize": 262144,
  "queryN1QLFeatCtrl": 76,
  "queryCurlWhitelist": {
    "all_access": false
  }
}

    Definitions

    This section describes the properties consumed and returned by this REST API.

    Access
    Settings

    Access

    Object

    Property Schema

    all_access
    required

    Defines whether the user has access to all URLs, or only URLs specified by the access list.

    This field set must be set to false to enable the allowed_urls and disallowed_urls fields.

    Setting this field to true enables access to all endpoints.

    Boolean

    allowed_urls
    optional

    An array of strings, each of which is a URL to which you wish to grant access. Each URL is a prefix match. The CURL() function will allow any URL that starts with this value.

    For example, if you wish to allow access to all Google APIs, add the URL https://maps.googleapis.com to the array. To allow complete access to localhost, use http://localhost.

    Note that each URL must include the port, protocol, and all other components of the URL.

    String array

    disallowed_urls
    optional

    An array of strings, each of which is a URL that will be restricted for all roles. Each URL is a prefix match. The CURL() function will disallow any URL that starts with this value.

    If both allowed_urls and disallowed_urls fields are populated, the disallowed_urls field takes precedence over allowed_urls.

    Note that each URL must include the port, protocol, and all other components of the URL.

    String array

    Settings

    Object

    Property Schema

    queryCleanupClientAttempts
    optional

    When enabled, the Query service preferentially aims to clean up just transactions that it has created, leaving transactions for the distributed cleanup process only when it is forced to.

    The node-level cleanupclientattempts setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: true
    Example: false

    Boolean

    queryCleanupLostAttempts
    optional

    When enabled, the Query service takes part in the distributed cleanup process, and cleans up expired transactions created by any client.

    The node-level cleanuplostattempts setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: true
    Example: false

    Boolean

    queryCleanupWindow
    optional

    Specifies how frequently the Query service checks its subset of active transaction records for cleanup. Decreasing this setting causes expiration transactions to be found more swiftly, with the tradeoff of increasing the number of reads per second used for the scanning process.

    The value for this setting is a string. Its format includes an amount and a mandatory unit, e.g. 10ms (10 milliseconds) or 0.5s (half a second). Valid units are:

    • ns (nanoseconds)
    • us (microseconds)
    • ms (milliseconds)
    • s (seconds)
    • m (minutes)
    • h (hours)

    The node-level cleanupwindow setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: "60s"
    Example: "30s"

    String (duration)

    queryCompletedLimit
    optional

    Sets the number of requests to be logged in the completed requests catalog. As new completed requests are added, old ones are removed.

    Increase this when the completed request keyspace is not big enough to track the slow requests, such as when you want a larger sample of slow requests.

    Refer to Configure the Completed Requests for more information and examples.

    The node-level completed-limit setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: 4000
    Example: 7000

    Integer (int32)

    queryCompletedMaxPlanSize
    optional

    A plan size in bytes. Limits the size of query execution plans that can be logged in the completed requests catalog. Values larger than the maximum limit are silently treated as the maximum limit. Queries with plans larger than this are not logged. You must obtain execution plans for such queries via profiling or using the EXPLAIN statement.

    Refer to Configure the Completed Requests for more information.

    The node-level completed-max-plan-size setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: 262144
    Minimum: 0
    Maximum: 20840448

    Integer (int32)

    queryCompletedThreshold
    optional

    A duration in milliseconds. All completed queries lasting longer than this threshold are logged in the completed requests catalog.

    Specify 0 to track all requests, independent of duration. Specify any negative number to track none.

    Refer to Configure the Completed Requests for more information and examples.

    The node-level completed-threshold setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: 1000
    Example: 7000

    Integer (int32)

    queryLogLevel
    optional

    Log level used in the logger.

    All values, in descending order of data:

    • DEBUG — For developers. Writes everything.

    • TRACE — For developers. Less info than DEBUG.

    • INFO — For admin & customers. Lists warnings & errors.

    • WARN — For admin. Only abnormal items.

    • ERROR — For admin. Only errors to be fixed.

    • SEVERE — For admin. Major items, like crashes.

    • NONE — Doesn't write anything.

    The node-level loglevel setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Values: "DEBUG", "TRACE", "INFO", "WARN", "ERROR", "SEVERE", "NONE"
    Default: "INFO"
    Example: "DEBUG"

    String

    queryMaxParallelism
    optional

    Specifies the maximum parallelism for queries on all Query nodes in the cluster.

    If the value is zero or negative, the maximum parallelism is restricted to the number of allowed cores. Similarly, if the value is greater than the number of allowed cores, the maximum parallelism is restricted to the number of allowed cores.

    (The number of allowed cores is the same as the number of logical CPUs. In Community Edition, the number of allowed cores cannot be greater than 4. In Enterprise Edition, there is no limit to the number of allowed cores.)

    Refer to Max Parallelism for more information.

    The node-level max-parallelism setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, there is a request-level max_parallelism parameter. If a request includes this parameter, it will be capped by the node-level max-parallelism setting.

    NOTE: To enable queries to run in parallel, you must specify the cluster-level queryMaxParallelism parameter, or specify the node-level max-parallelism parameter on all Query nodes.

    Default: 1
    Example: 0

    Integer (int32)

    queryMemoryQuota
    optional

    Specifies the maximum amount of memory a request may use on any Query node in the cluster, in MB.

    This parameter enforces a ceiling on the memory used for the tracked documents required for processing a request. It does not take into account any other memory that might be used to process a request, such as the stack, the operators, or some intermediate values.

    Within a transaction, this setting enforces the memory quota for the transaction by tracking the delta table and the transaction log (approximately).

    The node-level memory-quota setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, there is a request-level memory_quota parameter. If a request includes this parameter, it will be capped by the node-level memory-quota setting.

    Default: 0
    Example: 4

    Integer (int32)

    queryN1QLFeatCtrl
    optional

    SQL++ feature control. This setting is provided for technical support only.

    The node-level n1ql-feat-ctrl setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Integer (int32)

    queryNodeQuota
    optional

    Sets the soft memory limit for the Query service on every Query node in the cluster, in MB. The garbage collector tries to keep below this target. It is not a hard, absolute limit, and memory usage may exceed this value.

    When set to 0 (the default), the Query service sets a default soft memory limit for every node. To do this, the Query service calculates the difference between the total system RAM and 90% of the total system RAM:

    Total System RAM - (0.9 * Total System RAM)

    • If the difference is greater than 8 GiB, the default soft memory limit is set to the total system RAM minus 8 GiB.

    • If the difference is 8 GiB or less, the default soft memory limit is set to 90% of the total system RAM.

    The node-level node-quota setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: 0

    Integer (int32)

    queryNodeQuotaValPercent
    optional

    The percentage of the queryNodeQuota that is dedicated to tracked value content memory across all active requests for every Query node in the cluster. (The queryMemoryQuota setting specifies the maximum amount of document memory an individual request may use on any Query node in the cluster.)

    The node-level node-quota-val-percent setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: 67
    Minimum: 0
    Maximum: 100

    Integer (int32)

    queryNumAtrs
    optional

    Specifies the total number of active transaction records for all Query nodes in the cluster.

    The node-level numatrs setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, there is a request-level numatrs parameter. If a request includes this parameter, it will be capped by the node-level numatrs setting.

    Default: 1024
    Minimum: 0 (exclusive)
    Example: 512

    Integer (int32)

    queryNumCpus
    optional

    The number of CPUs the Query service can use on any Query node in the cluster. Note that this setting requires a restart of the Query service to take effect.

    When set to 0 (the default), the Query service can use all available CPUs, up to the limits described below.

    The number of CPUs can never be greater than the number of logical CPUs. In Community Edition, the number of allowed CPUs cannot be greater than 4. In Enterprise Edition, there is no limit to the number of allowed CPUs.

    The node-level num-cpus setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: 0

    Integer (int32)

    queryPipelineBatch
    optional

    Controls the number of items execution operators can batch for Fetch from the KV.

    The node-level pipeline-batch setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, the request-level pipeline_batch parameter specifies this property per request. The minimum of that and the node-level pipeline-batch setting is applied.

    Default: 16
    Example: 64

    Integer (int32)

    queryPipelineCap
    optional

    Maximum number of items each execution operator can buffer between various operators.

    The node-level pipeline-cap setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, the request-level pipeline_cap parameter specifies this property per request. The minimum of that and the node-level pipeline-cap setting is applied.

    Default: 512
    Example: 1024

    Integer (int32)

    queryPreparedLimit
    optional

    Maximum number of prepared statements in the cache. When this cache reaches the limit, the least recently used prepared statements will be discarded as new prepared statements are created.

    The node-level prepared-limit setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    Default: 16384
    Example: 65536

    Integer (int32)

    queryScanCap
    optional

    Maximum buffered channel size between the indexer client and the query service for index scans. This parameter controls when to use scan backfill.

    Use 0 or a negative number to disable. Smaller values reduce GC, while larger values reduce indexer backfill.

    The node-level scan-cap setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, the request-level scan_cap parameter specifies this property per request. The minimum of that and the node-level scan-cap setting is applied.

    Default: 512
    Example: 1024

    Integer (int32)

    queryTimeout
    optional

    Maximum time to spend on the request before timing out (ns).

    The value for this setting is an integer, representing a duration in nanoseconds. It must not be delimited by quotes, and must not include a unit.

    Specify 0 (the default value) or a negative integer to disable. When disabled, no timeout is applied and the request runs for however long it takes.

    The node-level timeout setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, the request-level timeout parameter specifies this property per request. The minimum of that and the node-level timeout setting is applied.

    Default: 0
    Example: 500000000

    Long (int64)

    queryTxTimeout
    optional

    Maximum time to spend on a transaction before timing out. This setting only applies to requests containing the BEGIN TRANSACTION statement, or to requests where the tximplicit parameter is set. For all other requests, it is ignored.

    The value for this setting is a string. Its format includes an amount and a mandatory unit, e.g. 10ms (10 milliseconds) or 0.5s (half a second). Valid units are:

    • ns (nanoseconds)
    • us (microseconds)
    • ms (milliseconds)
    • s (seconds)
    • m (minutes)
    • h (hours)

    Specify 0ms (the default value) to disable. When disabled, no timeout is applied and the transaction runs for however long it takes.

    The node-level txtimeout setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, there is a request-level txtimeout parameter. If a request includes this parameter, it will be capped by the node-level txtimeout setting.

    Default: "0ms"
    Example: "0.5s"

    String (duration)

    queryTmpSpaceDir
    optional

    The path to which the Index Service writes temporary backfill files, and the Query Service writes spill files, to store any transient data during query processing.

    The specified path must already exist. Only absolute paths are allowed.

    The default path is var/lib/couchbase/tmp within the Couchbase Server installation directory.

    Example: "/opt/couchbase/var/lib/couchbase/tmp"

    String

    queryTmpSpaceSize
    optional

    In MiB, the maximum size of temporary backfill files for each indexer, and the maximum size of temporary files for spilled sorting and other operations. In a cluster with both secondary indexing and full text search, the limit for disk space use is three times this setting.

    Setting the size to 0 disables backfill. Setting the size to -1 means the size is unlimited.

    The maximum size is limited only by the available disk space.

    Default: 5120
    Example: 2048

    Integer (int32)

    queryUseCBO
    optional

    Specifies whether the cost-based optimizer is enabled.

    The node-level use-cbo setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, the request-level use_cbo parameter specifies this property per request. If a request does not include this parameter, the node-level setting is used, which defaults to true.

    Default: true
    Example: false

    Boolean

    queryUseReplica
    optional

    Specifies whether a query can fetch data from a replica vBucket if active vBuckets are inaccessible. The possible values are:

    • off — read from replica is disabled for all queries and cannot be overridden at request level.

    • on — read from replica is enabled for all queries, but can be disabled at request level.

    • unset — read from replica is enabled or disabled at request level.

    Do not enable read from replica when you require consistent results. Only SELECT queries that are not within a transaction can read from replica.

    Reading from replica is only possible if the cluster uses Couchbase Server 7.6.0 or later.

    Note that KV range scans cannot currently be started on a replica vBucket. If a query uses sequential scan and a data node becomes unavailable, the query might return an error, even if read from replica is enabled for the request.

    The node-level use-replica setting specifies this property for a single node. When you change the cluster-level setting, the node-level setting is over-written for all nodes in the cluster.

    In addition, the request-level use_replica parameter specifies this property per request. If a request does not include this parameter, or if the request-level parameter is unset, the node-level setting is used. If the request-level parameter and the node-level setting are both unset, read from replica is disabled for that request.

    Values: "off", "on", "unset"
    Default: "unset"
    Example: "on"

    String

    queryCurlWhitelist
    optional

    An object which determines which URLs may be accessed by the CURL() function.

    Access

    Security

    The Query Settings REST API supports HTTP basic authentication. Pass your credentials through HTTP headers.

    Default

    Users must have one of the following RBAC roles:

    • Full Admin
    • Cluster Admin

    Type : http

    Refer to Roles for more details.

    See Also