Alexey Scherbakov created IGNITE-27435:
------------------------------------------
Summary: Optimize commit time for explicit RW transactions
Key: IGNITE-27435
URL: https://issues.apache.org/jira/browse/IGNITE-27435
Project: Ignite
Issue Type: Improvement
Reporter: Alexey Scherbakov
Fix For: 3.3
Currently explicit transaction is committed as soon as all write inflights are
completed.
This adds additional "tail" latency before beginning to commit.
This can be optimized in the following way:
1. Each inflight addtitionally tracks corresponding key in the tx inflight
context. A key is removed from the set as soon as inglight is replicated
2. We introduce addtitinal persisted tx state: COMMITTING
3. The a tx is started to commit, it synchronously replicates COMMITTING state
instead of COMMITED. Committing state additionally includes a list of keys (ack
list), which are being inflight just before commit starts.
4. Tx commit as acked to the user as soon as COMMITTING state is replicated and
all inflights are finished. This is "implicit commit".
5. As soon as tx is "implicitly committed", COMMITED state is replicated
asynchronously. After this, tx is considered "explicitely committed".
We need changes in tx recovery. When an abandoned write intent is encountered
and tx is in COMMITTING state and corresponding key is in the ack list, we need
to check if it is fully replicated. If no, tx is marked as rolled back.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
