* chore: upgrade Go to 1.19.3
This re-runs ./generate.sh and ./checkfmt.sh to format and update
source code (this is primarily responsible for the huge diff.)
* fix: update tests to reflect sorting algorithm change
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.
The cache defaulted to entry capacity size of 32. This default
is fine for lower cardinalities, but causes big spikes in InUse
heap with higher cardinalities that can OOM the process. Since
the hints had to be removed previously due to increased memory usage,
they are now completely removed. For lower cardinalities, we do
grow the slice, but this has a small performance penalty compared
to the large memory usage/OOMs with larger cardinalities.
This perioically re-allocates the cache store to avoid memory
fragmentation and gradual slow down of the store after repeated
deletes and inserts into the map.
There are several places in the code where comma-ok map retrieval was
being used poorly. Some were benign, like checking existence before
issuing an unconditional delete with no cleanup. Others were potentially
far more serious: assuming that if 'ok' was true, then the resulting
pointer retrieved from the map would be non-nil. `nil` is a perfectly
valid value to store in a map of pointers, and the comma-ok syntax is
meant for when membership is distinct from having a non-zero value.
There was only one or two cases that I saw that being used correctly for
maps of pointers.
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.
Brandon Pfeifer
Sam Arnold
Daniel Moran
michaelyou
Jason Wilder
Joe LeGasse
Stuart Carnie
Edd Robinson