Synapse can be quite memory intensive, and unless care is taken to tune
the GC thresholds it can end up thrashing, causing noticable performance
problems for large servers. We fix this by limiting how often we GC a
given generation, regardless of current counts/thresholds.
This does not help with the reverse problem where the thresholds are set
too high, but that should only happen in situations where they've been
manually configured.
Adds a `gc_min_seconds_between` config option to override the defaults.
Fixes#9890.
Part of #9744
Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.
`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
This PR modifies `GaugeBucketCollector` to only report data once it has been updated, rather than initially reporting a value of 0. Fixes zero values being reported for some metrics on startup until a background job to update the metric's value runs later.
- Update black version to the latest
- Run black auto formatting over the codebase
- Run autoformatting according to [`docs/code_style.md
`](80d6dc9783/docs/code_style.md)
- Update `code_style.md` docs around installing black to use the correct version
The main use case is to see how many requests are being made, and how
many are second/third/etc attempts. If there are large number of retries
then that likely indicates a delivery problem.
This was a bit unweildy for what I wanted: in particular, I wanted to assign
each measurement straight into a bucket, rather than storing an intermediate
Counter which didn't do any bucketing at all.
I've replaced it with something that is hopefully a bit easier to use.
(I'm not entirely sure what the difference between a HistogramMetricFamily and
a GaugeHistogramMetricFamily is, but given our counters can go down as well as
up the latter *sounds* more accurate?)
slots use less memory (and attribute access is faster) while slightly
limiting the flexibility of the class attributes. This focuses on objects
which are instantiated "often" and for short periods of time.
PyPy's gc.get_stats() returns an object containing detailed allocator statistics
which could be beneficial to collect as metrics.
Signed-off-by: Ivan Shapovalov <intelfx@intelfx.name>
Jonathan de Jong