Previously, the `checkpoint()` function determined the segments to drop
based on the current active transactions' WAL ID references. However, if
no transactions are active then the checkpoint would drop segments too
aggressively.
This changes the determination by using the highest WAL ID that is
actually checkpointed to disk to determine the high water mark. If no
page are checkpointed then no segments can be dropped.
green:
TestFragment_RowsIteration/combinations
TestFragment_RoaringImportTopN
red: (needs Ben's attention)
PILOSA_TXSRC=rbf go test -v -run TestFragment_TopN_IDs -tags=' shardwidth20' "-gcflags=all=-d=checkptr=0"
also red: (one for Ben)
TestCursor_FirstNext_Quick/9 is throwing
panic: cannot find segment containing WAL page: 1
as we check the error back from checkpoint() in Rollback().
back to github.com/dgraph-io/badger/v2 v2.0.1-rc1.0.20200709123515-8e896a7af361 b/c github.com/dgraph-io/badger/v2 v2.0.1-rc1.0.20200718033852-37ee16d8ad1c had issues with CI on 386 and arm
a) All tests green under -race for both PILOSA_TXSRC=roaring and PILOSA_TXSRC=badger.
b) Distinct is merged back into mainline pilosa.
Seebs notes on the Distinct work:
merge Distinct plugin back into main source tree, convert to Tx
We drop all references to the Preemptively Deprecated Don't You Dare
Use This extension interface, and move the one and only extension we had
(Distinct) into the main executor.
Also this fixes an arguable bug, which is that Container.AsBitmap()
would panic on a nil parameter, but it should have returned an empty
bitmap, because a nil *Ccontainer is a valid empty container. This
simplifies logic significantly in Distinct.
Fixes#569#570#571#572#573#584#585
The new logic to send resize instructions more makes it easier
to hit this, but it's probably always been a theoretically possible
bug to hit: If you are shutting a cluster down, then you stop accepting
connections, which means that if you have an existing resize job, you
can't get responses for it. Which means that the other nodes will
fail to notify you of the success or failure of resize instructions,
so the code waiting on the resize job's status waits forever.
When closing, we bail immediately on that; we don't need to wait for
those notifications. We still have a buffer, and a reasonable confidence
that we'll never write more than one result status, so if one of them
*does* somehow show up and cause the job to have a status,
writing the status won't block.
