3cff38ff94
Caught some typos. Made units separate from the numbers 1GHz -> 1 GHz after talking to Nick about questions of style (this has the side effect of making future spell checking easier).
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| layout | page_title | sidebar_current | description |
|---|---|---|---|
| docs | logs Stanza - Job Specification | docs-job-specification-logs | The "logs" stanza configures the log rotation policy for a task's stdout and stderr. Logging is enabled by default with sane defaults. The "logs" stanza allows for finer-grained control over how Nomad handles log files. |
logs Stanza
| Placement |
job -> group -> task -> **logs**
|
|---|
The logs stanza configures the log rotation policy for a task's stdout and
stderr. Logging is enabled by default with sane defaults (provided in the
parameters section below), and there is currently no way to disable logging for
tasks. The logs stanza allows for finer-grained control over how Nomad handles
log files.
Nomad's log rotation works by writing stdout/stderr output from tasks to a file
inside the alloc/logs/ directory with the following format:
<task-name>.<stdout/stderr>.<index>. Output is written to a particular index,
starting at zero, till that log file hits the configured max_file_size. After,
a new file is created at index + 1 and logs will then be written there. A log
file is never rolled over, instead Nomad will keep up to max_files worth of
logs and once that is exceeded, the log file with the lowest index is deleted.
job "docs" {
group "example" {
task "server" {
logs {
max_files = 10
max_file_size = 10
}
}
}
}
For information on how to interact with logs after they have been configured,
please see the nomad logs command.
logs Parameters
-
max_files(int: 10)- Specifies the maximum number of rotated files Nomad will retain forstdoutandstderr. Each stream is tracked individually, so specifying a value of 2 will create 4 files - 2 for stdout and 2 for stderr -
max_file_size(int: 10)- Specifies the maximum size of each rotated file inMB. If the amount of disk resource requested for the task is less than the total amount of disk space needed to retain the rotated set of files, Nomad will return a validation error when a job is submitted.
logs Examples
The following examples only show the logs stanzas. Remember that the
logs stanza is only valid in the placements listed above.
Configure Defaults
This example shows a default logging configuration. Yes, it is empty on purpose. Nomad automatically enables logging with sane defaults as described in the parameters section above.
Customization
This example asks Nomad to retain 3 rotated files for each of stderr and
stdout, each a maximum size of 5 MB per file. The minimum disk space this
would require is 60 MB (3 stderr + 3 stdout × 5 MB = 30 MB).
logs {
max_files = 3
max_file_size = 5
}