Main motivation was to has an ability to throttle background tasks, to
avoid affecting queries.
To new server settings had been added for this:
- max_mutations_bandwidth_for_server
- max_merges_bandwidth_for_server
Note, that they limit only reading, since usually you will not write
more data then you read, but sometimes it is possible in case of ALTER
UPDATE.
But for now, to keep things simple, I decided to limit this with only
2 settings instead of 4.
Note, that if the write throttling will be needed, then they can use the
same settings, and just create new throttler for write.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
One interesting thing about S3 C++ SDK is that it can read file multiple
times for calculating checksums and signature, but the last is not done
for the https protocol, though the checksum "could".
And indeed it does, since default checksum algorithm (MD5) does not
support streaming, and so it always calculated, regardless of the
protocol, however everything else (CRC*/SHA*) supports streamming and
actually will not be calculated for https at all!
This will be fixed in the follow up patch.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
