Upgrade RocksDB version from 6.29.5 to 7.6.0.

[ahamlat]

Signed-off-by: Ameziane H ameziane.hamlat@consensys.net

PR description

Upgrade RocksDB version from 6.29.5 to 7.6.0.

Fixed Issue(s)

Documentation

• I thought about documentation and added the doc-change-required label to this PR if
  updates are required.

Changelog

• I thought about the changelog and included a changelog update if required.

[ahamlat]

Upgrading RocksDB to version 7.6.0 give good results once the node is synced. The node had some GC issues at the beginning of sync but it was able to recover and sync faster. The only significant difference I see in RocksDB metrics is on read from SST files, RocksDB version 7.6.0 has 29 microseconds as 95 percentile against 159 microseconds for version 6.29.5. I will do more tests but it seems promising. I compared all the nodes I started that are currently synced and the one with version 7.6.0 has better performance, without high spec flag enabled. (I just noticed that the node with RocksDB version 6.29.5 has high spec enabled).

This seems to have also an impact if we upgrade the version on a synced node with an older RocksDB version, which means that we can can suggest this feature without syncing from scratch.

From what I read here, RocksDB supports backward compatibility and there may be some compatibility issues if there're some advanced RocksDB configurations, which is not the case with Besu. I did a sync from scratch and upgraded an already synced node, and in both cases I didn't notice any error related to RocksDB.

I will do more tests on different hardware specifications by combining with other RocksDB configurations that gave also good results.

[fab-10]

LGTM, just add a CHANGELOG entry for it

[ahamlat]

LGTM, just add a CHANGELOG entry for it

Done.