Address issues with Distinct failures in testing, or across shards, or in cases where the range of Distinct results is not the same as the range of shards available in any index.
If an index is provided to a bare distinct which happens
to be the index handling the query, then the query needs
to behave as if no index argument was provided.
For example:
When querying against index `i`,
```
Distinct(index="i", field="ints")`
```
should behave exactly like
```
Distinct(field="ints")
```
Problem: A top-level bare "Distinct" call returns results only
for shards on the current node.
Analysis: We don't actually want to limit Distinct calls to "available"
shards at all. We just want to run them on everything. But we already
did that in generating the precomputed results; all we need to do is,
if we get a non-shard-specific request for precomputed values, just
return all the values.
It's pretty hard to create logic for this using our fancy mapReduce,
but also we could just... not do that.
mergeBlock was bypassing the transaction setup stuff, which means that
if we ran out of open files, mergeBlock wouldn't generate ops log
entries (!), also it didn't update the cache (!). This came up because
it also didn't enjoy the "catch your segfaults and issue a diagnostic"
behavior offered by the generation code.
Switch to computing positions directly and calling importPositions,
which does a transaction.
UpdateEvery can change every key, and I think it strongly suggests no
reasonable expectation of repeated access to a previously-accessed key,
but also it can change the containers and replace them.
We were avoiding caching mapped containers in some but not all cases,
and that was causing segfaults. But really, the *problem* is that
the remap operation wasn't clearing (or updating) the cache. Cleaning
that up allows us to take advantage of the caching performance advantage
even when working with read-only/mapped bitmaps.
The only way to hit this:
* Have mmapped containers to begin with.
* Do reads so those containers get frozen.
* Access, either reading or writing, a specific container with key K.
* Snapshot, so the bitmap gets its containers replaced.
* Remember, they have to be frozen -- if they aren't frozen,
we'll update the containers in place.
* Now have GC run so it actually unmaps the data.
* Now try to write to the container with key K *before reading or
writing any other key*. You have to get through the whole snapshot
and GC process without any other reads or writes.
* You get the cached value. You try to use it. You explode.
The sliceContainers code was also setting lastKey to 0 in some cases,
but also setting lastContainer to nil, so this wouldn't have caused
problems, but just to be careful, I've standardized on ^uint64(0)
for everything.
This test is really a test of a very specific bit of the internals
of containers_btree/containers_slice, but we can't easily test it from
there because they don't have all the logic for remapping files.
The underlying issue is that they maintain a single-item "most recent
container" cache, and this wasn't getting updated during the remap
operations, happening through containers.UpdateEvery. The fix is
probably just to make sure that UpdateEvery invalidates the cache.
differenceInPlace wasn't checking for nil containers, which are
theoretically valid empty containers. Also added a couple of other
N==0 checks to streamline the higher-level operation.
- Remove YAML magic
- Remove a lot of duplication
- Update linter
- Use parameterized jobs and matrix build
- Update Docker Hub CD to produce versioned and "latest" images
- Add custom shard width test to workflow
This commit adds `TranslationSources` to the cluster
`ResizeInstruction`. These are the sources of translation
partitions which the receiving node needs in order to support
partition distribution in the new, resized cluster.
This also fixes a bug where index options were not being
encode in the proto Index object. That meant that the schema
transferred via protobuf was not correct. The reason why
things normally worked is because index creation typically
happens on the CreateIndex message, which does include the
options.
TODO:
- [ ] implement the TranslateStore interface for `InMemTranslateStore`
and `mock.TranslateStore`
- [ ] surely need some more tests around the `ReadFrom` and `WriteTo`
