summary refs log tree commit diff
path: root/docs/structured_logging.md
blob: d43dc9eb6ee88e5387c7e1c3ee09b413e23756e2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
# Structured Logging

A structured logging system can be useful when your logs are destined for a
machine to parse and process. By maintaining its machine-readable characteristics,
it enables more efficient searching and aggregations when consumed by software
such as the "ELK stack".

Synapse's structured logging system is configured via the file that Synapse's
`log_config` config option points to. The file should include a formatter which
uses the `synapse.logging.TerseJsonFormatter` class included with Synapse and a
handler which uses the above formatter.

There is also a `synapse.logging.JsonFormatter` option which does not include
a timestamp in the resulting JSON. This is useful if the log ingester adds its
own timestamp.

A structured logging configuration looks similar to the following:

```yaml
version: 1

formatters:
    structured:
        class: synapse.logging.TerseJsonFormatter

handlers:
    file:
        class: logging.handlers.TimedRotatingFileHandler
        formatter: structured
        filename: /path/to/my/logs/homeserver.log
        when: midnight
        backupCount: 3  # Does not include the current log file.
        encoding: utf8

loggers:
    synapse:
        level: INFO
        handlers: [remote]
    synapse.storage.SQL:
        level: WARNING
```

The above logging config will set Synapse as 'INFO' logging level by default,
with the SQL layer at 'WARNING', and will log to a file, stored as JSON.

It is also possible to configure Synapse to log to a remote endpoint by using the
`synapse.logging.RemoteHandler` class included with Synapse. It takes the
following arguments:

- `host`: Hostname or IP address of the log aggregator.
- `port`: Numerical port to contact on the host.
- `maximum_buffer`: (Optional, defaults to 1000) The maximum buffer size to allow.

A remote structured logging configuration looks similar to the following:

```yaml
version: 1

formatters:
    structured:
        class: synapse.logging.TerseJsonFormatter

handlers:
    remote:
        class: synapse.logging.RemoteHandler
        formatter: structured
        host: 10.1.2.3
        port: 9999

loggers:
    synapse:
        level: INFO
        handlers: [remote]
    synapse.storage.SQL:
        level: WARNING
```

The above logging config will set Synapse as 'INFO' logging level by default,
with the SQL layer at 'WARNING', and will log JSON formatted messages to a
remote endpoint at 10.1.2.3:9999.