|
| 1 | +--- |
| 2 | +navigation_title: "Query log" |
| 3 | +--- |
| 4 | + |
| 5 | +# {{esql}} Query log [esql-query-log] |
| 6 | + |
| 7 | + |
| 8 | +The {{esql}} query log allows to log {{esql}} queries based on their execution time. |
| 9 | + |
| 10 | +You can use these logs to investigate, analyze or troubleshoot your cluster’s historical {{esql}} performance. |
| 11 | + |
| 12 | +{{esql}} query log reports task duration at coordinator level, but might not encompass the full task execution time observed on the client. For example, logs don’t surface HTTP network delays. |
| 13 | + |
| 14 | +Events that meet the specified threshold are emitted into [{{es}} server logs](docs-content://deploy-manage/monitor/logging-configuration/update-elasticsearch-logging-levels.md). |
| 15 | + |
| 16 | +These logs can be found in local {{es}} service logs directory. Slow log files have a suffix of `_esql_querylog.json`. |
| 17 | + |
| 18 | +## Query log format [query-log-format] |
| 19 | + |
| 20 | +The following is an example of a successful query event in the query log: |
| 21 | + |
| 22 | +```js |
| 23 | +{ |
| 24 | + "@timestamp": "2025-03-11T08:39:50.076Z", |
| 25 | + "log.level": "TRACE", |
| 26 | + "auth.type": "REALM", |
| 27 | + "elasticsearch.querylog.planning.took": 3108666, |
| 28 | + "elasticsearch.querylog.planning.took_millis": 3, |
| 29 | + "elasticsearch.querylog.query": "from index | limit 100", |
| 30 | + "elasticsearch.querylog.search_type": "ESQL", |
| 31 | + "elasticsearch.querylog.success": true, |
| 32 | + "elasticsearch.querylog.took": 8050416, |
| 33 | + "elasticsearch.querylog.took_millis": 8, |
| 34 | + "user.name": "elastic-admin", |
| 35 | + "user.realm": "default_file", |
| 36 | + "ecs.version": "1.2.0", |
| 37 | + "service.name": "ES_ECS", |
| 38 | + "event.dataset": "elasticsearch.esql_querylog", |
| 39 | + "process.thread.name": "elasticsearch[runTask-0][esql_worker][T#12]", |
| 40 | + "log.logger": "esql.querylog.query", |
| 41 | + "elasticsearch.cluster.uuid": "KZo1V7TcQM-O6fnqMm1t_g", |
| 42 | + "elasticsearch.node.id": "uPgRE2TrSfa9IvnUpNT1Uw", |
| 43 | + "elasticsearch.node.name": "runTask-0", |
| 44 | + "elasticsearch.cluster.name": "runTask" |
| 45 | +} |
| 46 | +``` |
| 47 | + |
| 48 | +The following is an example of a failing query event in the query log: |
| 49 | + |
| 50 | +```js |
| 51 | +{ |
| 52 | + "@timestamp": "2025-03-11T08:41:54.172Z", |
| 53 | + "log.level": "TRACE", |
| 54 | + "auth.type": "REALM", |
| 55 | + "elasticsearch.querylog.error.message": "line 1:15: mismatched input 'limitxyz' expecting {DEV_CHANGE_POINT, 'enrich', 'dissect', 'eval', 'grok', 'limit', 'sort', 'stats', 'where', DEV_INLINESTATS, DEV_FORK, 'lookup', DEV_JOIN_LEFT, DEV_JOIN_RIGHT, DEV_LOOKUP, 'mv_expand', 'drop', 'keep', DEV_INSIST, 'rename'}", |
| 56 | + "elasticsearch.querylog.error.type": "org.elasticsearch.xpack.esql.parser.ParsingException", |
| 57 | + "elasticsearch.querylog.query": "from person | limitxyz 100", |
| 58 | + "elasticsearch.querylog.search_type": "ESQL", |
| 59 | + "elasticsearch.querylog.success": false, |
| 60 | + "elasticsearch.querylog.took": 963750, |
| 61 | + "elasticsearch.querylog.took_millis": 0, |
| 62 | + "user.name": "elastic-admin", |
| 63 | + "user.realm": "default_file", |
| 64 | + "ecs.version": "1.2.0", |
| 65 | + "service.name": "ES_ECS", |
| 66 | + "event.dataset": "elasticsearch.esql_querylog", |
| 67 | + "process.thread.name": "elasticsearch[runTask-0][search][T#16]", |
| 68 | + "log.logger": "esql.querylog.query", |
| 69 | + "elasticsearch.cluster.uuid": "KZo1V7TcQM-O6fnqMm1t_g", |
| 70 | + "elasticsearch.node.id": "uPgRE2TrSfa9IvnUpNT1Uw", |
| 71 | + "elasticsearch.node.name": "runTask-0", |
| 72 | + "elasticsearch.cluster.name": "runTask" |
| 73 | +} |
| 74 | +``` |
| 75 | + |
| 76 | + |
| 77 | +## Enable query logging [enable-query-log] |
| 78 | + |
| 79 | +You can enable query logging at cluster level. |
| 80 | + |
| 81 | +By default, all thresholds are set to `-1`, which results in no events being logged. |
| 82 | + |
| 83 | +Query log thresholds can be enabled for the four logging levels: `trace`, `debug`, `info`, and `warn`. |
| 84 | + |
| 85 | +To view the current query log settings, use the [get cluster settings API](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-cluster-get-settings): |
| 86 | + |
| 87 | +```console |
| 88 | +GET _cluster/settings?filter_path=*.esql.querylog.* |
| 89 | +``` |
| 90 | + |
| 91 | +You can use the `esql.querylog.include.user` setting to append `user.*` and `auth.type` fields to slow log entries. These fields contain information about the user who triggered the request. |
| 92 | + |
| 93 | +The following snippet adjusts all available {{esql}} query log settings [update cluster settings API](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-cluster-put-settings): |
| 94 | + |
| 95 | +```console |
| 96 | +PUT /_cluster/settings |
| 97 | +{ |
| 98 | + "transient": { |
| 99 | + "esql.querylog.threshold.warn": "10s", |
| 100 | + "esql.querylog.threshold.info": "5s", |
| 101 | + "esql.querylog.threshold.debug": "2s", |
| 102 | + "esql.querylog.threshold.trace": "500ms", |
| 103 | + "esql.querylog.include.user": true |
| 104 | + } |
| 105 | +} |
| 106 | +``` |
| 107 | + |
| 108 | + |
| 109 | + |
| 110 | +## Best practices for query logging [troubleshoot-query-log] |
| 111 | + |
| 112 | +Logging slow requests can be resource intensive to your {{es}} cluster depending on the qualifying traffic’s volume. For example, emitted logs might increase the index disk usage of your [{{es}} monitoring](docs-content://deploy-manage/monitor/stack-monitoring.md) cluster. To reduce the impact of slow logs, consider the following: |
| 113 | + |
| 114 | +* Set high thresholds to reduce the number of logged events. |
| 115 | +* Enable slow logs only when troubleshooting. |
| 116 | + |
| 117 | +If you aren’t sure how to start investigating traffic issues, consider enabling the `warn` threshold with a high `30s` threshold at the index level using the [update cluster settings API](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-cluster-put-settings): |
| 118 | + |
| 119 | +Here is an example of how to change cluster settings to enable query logging at `warn` level, for queries taking more than 30 seconds, and include user information in the logs: |
| 120 | + |
| 121 | +```console |
| 122 | +PUT /_cluster/settings |
| 123 | +{ |
| 124 | + "transient": { |
| 125 | + "esql.querylog.include.user": true, |
| 126 | + "esql.querylog.threshold.warn": "30s" |
| 127 | + } |
| 128 | +} |
| 129 | +``` |
| 130 | + |
0 commit comments