This change delays Tag cloning until a new series is found, and will
only clone Tags acquired from `ParsePoints...` and not those referencing
the mmap-ed files (TSM) that are created on startup.
This leak seems to have been introduced in 8aa224b22d,
present in 1.1.0 and 1.1.1.
When points were parsed from HTTP payloads, their tags and fields
referred to subslices of the request body; if any tag set introduced a
new series, then those tags then were stored in the in-memory series
index objects, preventing the HTTP body from being garbage collected. If
there were no new series in the payload, then the request body would be
garbage collected as usual.
Now, we clone the tags before we store them in the index. This is an
imperfect fix because the Point still holds references to the original
tags, and the Point's field iterator also refers to the payload buffer.
However, the current write code path does not retain references to the
Point or its fields; and this change will likely be obsoleted when TSI
is introduced.
This change likely fixes#7827, #7810, #7778, and perhaps others.
This change adds some very basic name validation with the following
plain-english description: names must be non-zero sequence of printable
characters that do not contain slashes ('/' or '\') and are not equal to
either "." or "..".
The intent is that, since we currently just use database and retention
policy names directly as path elements, these rules will hopefully leave
us with names that should be at least close to valid directory names.
Ideally, we would restrict names even further or not use them as path
elements directly, but this should be a step towards the former without
restricting names "too much"
Fixes#7822
This change first ensures that databases and retention policies exist
before attempting to remove them from the Store. It also adds some
checks in the `DeleteDatabase` and `DeleteRetentionPolicy` to ensure
that maliciously named entries won't remove anything outside of the
configured data directory.
I ran into an issue where the cache snapshotting seemed to stop
completely causing the cache to fill up and never recover. I believe
this is due to the the Timer being reused incorrectly. Instead,
use a Ticker that will fire more regularly and not require the resetting
logic (which was wrong).
The memory stats as well as the size of the cache were not accurate.
There was also a problem where the cache size would be increased
optimisitically, but if the cache size limit was hit, it would not
be decreased. This would cause the cache size to grow without
bounds with every failed write.
The CacheKeyIterator (used for snapshot compactions), iterated over
each key and serially encoded the values for that key as the TSM
file is written. With many series, this can be slow and will only
use 1 CPU core even if more are available.
This changes it so that the key space is split amongst a number of
goroutines that start encoding all keys in parallel to improve
throughput.
This simplifies the cache.Snapshot func to swap the hot cache to
the snapshot cache instead of copy and appending entries. This
reduces the amount of time the cache is write locked which should
reduce cache contention for the read only code paths.
Also, fix the `Iterators.Merge(IteratorOptions)` function so it consults
the `Ordered` attribute to determine which iterator it should use to
merge the input iterators.
The backup command can fail if a snapshot is running which silently
closes the connection. This causes the backup shard command to continue
on as if nothing failed.
This adds query syntax support for subqueries and adds support to the
query engine to execute queries on subqueries.
Subqueries act as a source for another query. It is the equivalent of
writing the results of a query to a temporary database, executing
a query on that temporary database, and then deleting the database
(except this is all performed in-memory).
The syntax is like this:
SELECT sum(derivative) FROM (SELECT derivative(mean(value)) FROM cpu GROUP BY *)
This will execute derivative and then sum the result of those derivatives.
Another example:
SELECT max(min) FROM (SELECT min(value) FROM cpu GROUP BY host)
This would let you find the maximum minimum value of each host.
There is complete freedom to mix subqueries with auxiliary fields. The only
caveat is that the following two queries:
SELECT mean(value) FROM cpu
SELECT mean(value) FROM (SELECT value FROM cpu)
Have different performance characteristics. The first will calculate
`mean(value)` at the shard level and will be faster, especially when it comes to
clustered setups. The second will process the mean at the top level and will not
include that optimization.
The previous implementation was susceptible to a race condition (of
correctness) since c.decreaseSize is called without a lock in
(*Cache).WriteMulti.
There were already tests which asserted the correctness of the result of
decreaseSize, so no tests were added or modified.
It looks like the real import path to the project is go.uber.org/zap
instead of github.com/uber-go/zap since the example in the project
references that path.
Currently, whenever a snapshot occurs the Cache is reset and so many
allocations are repeated, as the same type of data is re-added to
the Cache.
This commit allows the stores to keep track of the number of values
within an entry, and use that size as a hint when the same entry needs
to be recreated after a snapshot.
To avoid hints persisting over a long period of time they are deleting
after every snapshot, and rebuilt using the most recent entries only.
Edd Robinson
Cory LaNou
Gunnar
Joe LeGasse
Mark Rushakoff
Jason Wilder
Jonathan A. Sternberg
Mark Rushakoff
Gustav Westling