Hi Ivan!
In my opinion we need to preserve the essence of the metrics: if we
didn't consider dirty writes as updates before MVCC implementation, we
also shouldn't count these writes in MVCC metrics implementation too.
So, I think we need to count only committed entries. But we can count
this dirty writes as additional metrics.
Also additional metrics concerning MVCC could be:
- Average count of the active transactions per snapshot
- Average quantity of versions per key
--
Roman Kondakov
On 07.08.2018 17:17, Павлухин Иван wrote:
Hi Igniters,
I am working on cache metrics support for caches with enabled MVCC. As you
may know, during MVCC transaction execution entry versions are written to
storage right away (without deferring until commit). So, it is not obvious
for me if we should update writes count right away or defer it until
commit. On one hand, MVCC entry version write is not "true" write until
commit. On the other hand, it definitely changes the storage. How do we
interpret write metrics in Ignite philosophy?
Also, it seems that bunch of MVCC specific metrics could be introduced. I
would like to collect some thoughts about it. Which such metrics come to
your mind?
