Fixing the config/config_test, the discovery/file/file_test and the
promql/promql_test tests for Windows. For most of the tests, the fix involved
correct handling of path separators. In the case of the promql tests, the
issue was related to the removal of the temporal directories used by the
storage. The issue is that the RemoveAll() call returns an error when it
tries to remove a directory which is not empty, which seems to be true due to
some kind of process that is still running after closing the storage. To fix
it I added some retries to the remove of the temporal directories.
Adding tags file from Universal Ctags to .gitignore
If the storage deprecates a ref, we have to re-insert with the full
label set. Typically that doesn't correlate with a new series being
created.
We can still use the allocated label set from before.
Let older head blocks be compacted once the newest once has samples at
50% of its total range. This allows the memory of the compacted blocks
to be released and garbage collected before a new head block gets
created. Thereby the number of head blocks is 1 or 2 instead of 2 or 3
and memory spikes are reduced.
The changes [1][] to Marathon service discovery to support multiple
ports mean that Prometheus now attempts to scrape all ports belonging to
a Marathon service.
You can use port definition or port mapping labels to filter out which
ports to scrape but that requires service owners to update their
Marathon configuration.
To allow for a smoother migration path, add a
`__meta_marathon_port_index` label, whose value is set to the port's
sequential index integer. For example, PORT0 has the value `0`, PORT1
has the value `1`, and so on.
This allows you to support scraping both the first available port (the
previous behaviour) in addition to ports with a `metrics` label.
For example, here's the relabel configuration we might use with
this patch:
- action: keep
source_labels: ['__meta_marathon_port_definition_label_metrics', '__meta_marathon_port_mapping_label_metrics', '__meta_marathon_port_index']
# Keep if port mapping or definition has a 'metrics' label with any
# non-empty value, or if no 'metrics' port label exists but this is the
# service's first available port
regex: ([^;]+;;[^;]+|;[^;]+;[^;]+|;;0)
This assumes that the Marathon API returns the ports in sorted order
(matching PORT0, PORT1, etc), which it appears that it does.
[1]: https://github.com/prometheus/prometheus/pull/2506