This commit refactors the block checksumming by removing the
iteration over each block and instead only checking blocks which
have data. This requires merging the cache inspection with the
roaring iterator to reduce CPU time and memory allocations.
This commit adds a `Closing` channel to the `IndexSyncer` and the
`FragmentSyncer` that is periodically checked during execution.
If the channel is closed then an in-progress sync is immediately
stopped.
This commit adds a fast path for optimizing queries that only
have `SetBitmapAttrs()` calls in them. It does this by grouping
the calls into a single Bolt transaction and also by merging
multiple attribute updates per ID into one update.
This commit changes the `roaring.Bitmap` to use a 40/24 split in
the high and low bits. This change also requires the low bits
to use `uint32` instead of `uint16`.
This commit moves bitmap intersection into the `roaring` package
in order to reduce allocations.
Benchmarks against real world datasets show a speed improvement of
353%. Previously, intersection operated at approximately 5.6M
bits/sec against two 60K bit bitmaps with 30% overlap. The new
intersection operates at approximately 20M bits/sec.
This commit changes the fragment allocation algorithm in the cluster
to make use of the `DB` name. This allows each database to use a
different slice distribution.
Initially, the `frame` was going to be used for allocation, however,
this was problematic since queries can span multiple frames so it's
impossible to choose a single frame to use.
This commit moves the computation of the intersection count to
the `roaring` package so that no allocations are required. The
implementation operates at the roaring container level and has
specialized functions for array-array, array-bitmap, and
bitmap-bitmap container pairs.
This commit changes the underlying storage for `Bitmap` from a
red-black tree to a roaring bitmap. It also removes bitmaps from
the cache and only stores the bitmap count.
This commit refactors the anti-entropy system to fetch data from
all replicated blocks and only set/clear bits which deviate from
the consensus between all blocks.
An example of this is if 3 nodes had the following bits set for
a single bitmap:
Node A: 1 2 3
Node B: 2 4
Node C: 1 2 4
Then only bits which are set on a majority will be set. In this
case bits 1, 2, & 4 are set but 3 only exists on a single node.
The node performing the merge would then determine the following
set/clear diffs for each node:
Node A: clear(3), set(4)
Node B: set(1)
Node C: none
Once the merge is performed and all nodes receive their diff
instructions then the nodes will be in sync:
Node A: 1 2 4
Node B: 1 2 4
Node C: 1 2 4
There still exists situations where bits can be reset. If Node A
is up and Node B & C are down then Node A's bits will be reset
once B & C come back online. We should add write consistency
settings for incoming writes so that we can ensure that a quorum
is written to before returning a success. This is outside the
scope of this commit though.
