81 lines
2.5 KiB
Markdown
81 lines
2.5 KiB
Markdown
# Structured Logging
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A structured logging system can be useful when your logs are destined for a
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machine to parse and process. By maintaining its machine-readable characteristics,
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it enables more efficient searching and aggregations when consumed by software
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such as the [ELK stack](https://opensource.com/article/18/9/open-source-log-aggregation-tools).
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Synapse's structured logging system is configured via the file that Synapse's
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`log_config` config option points to. The file should include a formatter which
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uses the `synapse.logging.TerseJsonFormatter` class included with Synapse and a
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handler which uses the above formatter.
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There is also a `synapse.logging.JsonFormatter` option which does not include
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a timestamp in the resulting JSON. This is useful if the log ingester adds its
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own timestamp.
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A structured logging configuration looks similar to the following:
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```yaml
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version: 1
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formatters:
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structured:
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class: synapse.logging.TerseJsonFormatter
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handlers:
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file:
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class: logging.handlers.TimedRotatingFileHandler
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formatter: structured
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filename: /path/to/my/logs/homeserver.log
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when: midnight
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backupCount: 3 # Does not include the current log file.
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encoding: utf8
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loggers:
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synapse:
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level: INFO
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handlers: [remote]
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synapse.storage.SQL:
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level: WARNING
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```
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The above logging config will set Synapse as 'INFO' logging level by default,
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with the SQL layer at 'WARNING', and will log to a file, stored as JSON.
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It is also possible to configure Synapse to log to a remote endpoint by using the
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`synapse.logging.RemoteHandler` class included with Synapse. It takes the
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following arguments:
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- `host`: Hostname or IP address of the log aggregator.
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- `port`: Numerical port to contact on the host.
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- `maximum_buffer`: (Optional, defaults to 1000) The maximum buffer size to allow.
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A remote structured logging configuration looks similar to the following:
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```yaml
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version: 1
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formatters:
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structured:
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class: synapse.logging.TerseJsonFormatter
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handlers:
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remote:
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class: synapse.logging.RemoteHandler
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formatter: structured
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host: 10.1.2.3
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port: 9999
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loggers:
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synapse:
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level: INFO
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handlers: [remote]
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synapse.storage.SQL:
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level: WARNING
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```
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The above logging config will set Synapse as 'INFO' logging level by default,
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with the SQL layer at 'WARNING', and will log JSON formatted messages to a
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remote endpoint at 10.1.2.3:9999.
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