Last week in scylla.git master (issue #72; 2021-04-04)
Avi Kivity
<avi@scylladb.com>This short report brings to light some interesting commits to
scylla.git master from the last week. Commits in the
ec4d91f9ebef..f186de909d range are covered.
There were 102 non-merge commits from 15 authors in that period.
Some notable commits:
The enable_sstables_mc_format configuration parameter is
now ignored; mc or md format is mandatory. Scylla continues
to be able to read older ka and la format sstables.
The Raft implementation now updates
RPC about new and removed nodes.
Thrift has now partial
admission control, to reduce the chance of server overload.
Also, the Thrift listen port is now disabled
by default, as it is not often used. Thrift is still fully
supported.
Streams of mutation data are represented in Scylla by a
flat_mutation_reader, which provides a means for a function to
consume a stream. This was made
faster, which improves operations such as flushing a
memtable.
When Scylla receives sstables from outside the replica (such as
via a repair operation, or after restoring a snapshot) it first
reshapes them to conform to the compaction strategy. It now does
this more
efficiently for Leveled Compaction Strategy, by checking
first if the sstables happen to be disjoint.
There is now documentation
for the fast mode of the slow query logging feature.
More code paths can now work with non-contiguous memory for table
columns and intermediate values: comparing
values, the CQL
write path. This reduces CPU stalls due to memory allocation
when large blobs are present.