Commit graph

14 commits

Author SHA1 Message Date
Julius Volz 740d448983 Use custom timestamp type for sample timestamps and related code.
So far we've been using Go's native time.Time for anything related to sample
timestamps. Since the range of time.Time is much bigger than what we need, this
has created two problems:

- there could be time.Time values which were out of the range/precision of the
  time type that we persist to disk, therefore causing incorrectly ordered keys.
  One bug caused by this was:

  https://github.com/prometheus/prometheus/issues/367

  It would be good to use a timestamp type that's more closely aligned with
  what the underlying storage supports.

- sizeof(time.Time) is 192, while Prometheus should be ok with a single 64-bit
  Unix timestamp (possibly even a 32-bit one). Since we store samples in large
  numbers, this seriously affects memory usage. Furthermore, copying/working
  with the data will be faster if it's smaller.

*MEMORY USAGE RESULTS*
Initial memory usage comparisons for a running Prometheus with 1 timeseries and
100,000 samples show roughly a 13% decrease in total (VIRT) memory usage. In my
tests, this advantage for some reason decreased a bit the more samples the
timeseries had (to 5-7% for millions of samples). This I can't fully explain,
but perhaps garbage collection issues were involved.

*WHEN TO USE THE NEW TIMESTAMP TYPE*
The new clientmodel.Timestamp type should be used whenever time
calculations are either directly or indirectly related to sample
timestamps.

For example:
- the timestamp of a sample itself
- all kinds of watermarks
- anything that may become or is compared to a sample timestamp (like the timestamp
  passed into Target.Scrape()).

When to still use time.Time:
- for measuring durations/times not related to sample timestamps, like duration
  telemetry exporting, timers that indicate how frequently to execute some
  action, etc.

*NOTE ON OPERATOR OPTIMIZATION TESTS*
We don't use operator optimization code anymore, but it still lives in
the code as dead code. It still has tests, but I couldn't get all of them to
pass with the new timestamp format. I commented out the failing cases for now,
but we should probably remove the dead code soon. I just didn't want to do that
in the same change as this.

Change-Id: I821787414b0debe85c9fffaeb57abd453727af0f
2013-12-03 09:11:28 +01:00
Julius Volz eb461a707d Add chunk sanity checking to dumper tool.
Also, move codecs/filters to common location so they can be used in subsequent
test.

Change-Id: I3ffeb09188b8f4552e42683cbc9279645f45b32e
2013-10-23 01:06:49 +02:00
Julius Volz 0003027dce Add needed trailing spaces in logs. 2013-08-12 18:22:48 +02:00
Julius Volz aa5d251f8d Use github.com/golang/glog for all logging. 2013-08-12 17:54:36 +02:00
Julius Volz b9c90925dd Add simple rule file checker tool.
This tool does the simple job of checking a Prometheus rule file for validity
and printing the parsed rules if the loading succeeds. This came out of
an immediate need to quickly verify changes to existing rule files.
2013-08-06 18:42:33 +02:00
Matt T. Proud cc989c68e1 Replace direct curation table access with wrapper. 2013-08-06 12:02:52 +02:00
Matt T. Proud 07ac921aec Code Review: First pass. 2013-08-05 17:31:49 +02:00
Matt T. Proud 30b1cf80b5 WIP - Snapshot of Moving to Client Model. 2013-06-25 15:52:42 +02:00
Johannes 'fish' Ziemke 56249320e3 Remove gvm on travis. 2013-06-13 14:36:00 +02:00
Johannes 'fish' Ziemke 4524a5fe37 Remove gvm and install go by hand. 2013-06-12 18:39:37 +02:00
Matt T. Proud a73f061d3c Persist solely Protocol Buffers.
An design question was open for me in the beginning was whether to
serialize other types to disk, but Protocol Buffers quickly won out,
which allows us to drop support for other types.  This is a good
start to cleaning up a lot of cruft in the storage stack and
can let us eventually decouple the various moving parts into
separate subsystems for easier reasoning.

This commit is not strictly required, but it is a start to making
the rest a lot more enjoyable to interact with.
2013-06-08 11:02:35 +02:00
Julius Volz 6d68626125 Simple LevelDB sample dumper tool.
This very simple tool dumps all samples in a LevelDB metrics storage
together with their chunk information. This is very crude for now - I
just whipped it up because I needed to debug something. We should add
printf-style formatting support for it in the future to indicate what
information to output for each sample in the database. We could also
support inspecting the index databases.
2013-05-22 16:12:39 +02:00
Matt T. Proud 1f7f89b4e3 Simplify compaction and expose database sizes.
This commit simplifies the way that compactions across a database's
keyspace occur due to reading the LevelDB internals.  Secondarily it
introduces the database size estimation mechanisms.
2013-05-13 13:15:35 +02:00
Matt T. Proud fa6a1f97d0 Expose interfaces for pruner and make pruner tool.
In order to run database cleanups and diagnostics, we should have
a means for pruning a database---even if LevelDB does this for us.
2013-05-10 17:07:03 +02:00