* fix(influxd): update xxhash, avoid stringtoslicebyte in cache (#578)
* fix(influxd): update xxhash, avoid stringtoslicebyte in cache
This commit does 3 things:
* it updates xxhash from v1 to v2; v2 includes a assembly arm version of
Sum64
* it changes the cache storer to write with a string key instead of a
byte slice. The cache only reads the key which WriteMulti already has
as a string so we can avoid a host of allocations when converting back
and forth from immutable strings to mutable byte slices. This includes
updating the cache ring and ring partition to write with a string key
* it updates the xxhash for finding the cache ring partition to use
Sum64String which uses unsafe pointers to directly use a string as a
byte slice since it only reads the string. Note: this now uses an
assembly version because of the v2 xxhash update. Go 1.22 included new
compiler ability to recognize calls of Method([]byte(myString)) and not
make a copy but from looking at the call sites, I'm not sure the
compiler would recognize it as the conversion to a byte slice was
happening several calls earlier.
That's what this change set does. If we are uncomfortable with any of
these, we can do fewer of them (for example, not upgrade xxhash; and/or
not use the specialized Sum64String, etc).
For the performance issue in maz-rr, I see converting string keys to
byte slices taking between 3-5% of cpu usage on both the primary and
secondary. So while this pr doesn't address directly the increased cpu
usage on the secondary, it makes cpu usage less on both which still
feels like a win. I believe these changes are easier to review that
switching to a byte slice pool that is likely needed in other places as
the compiler provides nearly all of the correctness checks we need (we
are relying also on xxhash v2 being correct).
* helps #550
* chore: fix tests/lint
* chore: don't use assembly version; should inline
This 2 line change causes xxhash to use a purego Sum64 implementation
which allows the compiler to see that Sum64 only read the byte slice
input which them means is can skip the string to byte slice allocation
and since it can skip that, it should inline all the calls to
getPartitionStringKey and Sum64 avoiding 1 call to Sum64String which
isn't inlined.
* chore: update ci build file
the ci build doesn't use the make file!!!
* chore: revert "chore: update ci build file"
This reverts commit 94be66fde03e0bbe18004aab25c0e19051406de2.
* chore: revert "chore: don't use assembly version; should inline"
This reverts commit 67d8d06c02e17e91ba643a2991e30a49308a5283.
(cherry picked from commit 1d334c679ca025645ed93518b7832ae676499cd2)
* feat: need to update go sum
---------
Co-authored-by: Phil Bracikowski <13472206+philjb@users.noreply.github.com>
The large number of partitions cause big HeapInUse swings at higher
cardinality which can lead to OOMs. Reducing this to 16 lowers
write throughput to some extent at lower cardinalities, keeps memory
more stable over the long run.
This switches all the interfaces that take string series key to
take a []byte. This eliminates many small allocations where we
convert between to two repeatedly. Eventually, this change should
propogate futher up the stack.
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.
WeblWabl
Sam Arnold
Daniel Moran
Stuart Carnie
Mark Rushakoff
Jason Wilder
Edd Robinson