- In general, it is expected that clickhouse-*-bridges and
clickhouse-server were build from the same source version (e.g. are
upgraded "atomically"). If that is not the case, we should at least
be able to detect the mismatch and abort.
- This commit adds a URL parameter "version", defined in a header shared
by the server and bridges. The bridge returns an error in case of
mismatch.
- The version is *not* send and checked for "ping" requests (used for
handshake), only for regular requests send after handshake. This is
because the internally thrown server-side exception due to HTTP
failure does not propagate the exact HTTP error (it only stores the
error as text), and as a result, the server-side handshake code
simply retries in case of error with exponential backoff and finally
fails with a "timeout error". This is reasonable as pings typically
fail due to time out. However, without a rework of HTTP exceptions,
version mismatch during ping would also appear as "timeout" which is
too misleading. The behavior may be changed later if needed.
- Note that introducing a version parameter does not represent a
protocol upgrade itself. Bridges older than the server will simply
ignore the field. Only servers older than the bridges receive an error
but such a situation should never occur in practice.
The following new provile events had been added:
- FileSync - Number of times the F_FULLFSYNC/fsync/fdatasync function was called for files.
- DirectorySync - Number of times the F_FULLFSYNC/fsync/fdatasync function was called for directories.
- FileSyncElapsedMicroseconds - Total time spent waiting for F_FULLFSYNC/fsync/fdatasync syscall for files.
- DirectorySyncElapsedMicroseconds - Total time spent waiting for F_FULLFSYNC/fsync/fdatasync syscall for directories.
v2: rewrite test to sh with retries
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
- Introduced with the C++20 <bit> header
- The problem with __builtin_c(l|t)z() is that 0 as input has an
undefined result (*) and the code did not always check. The std::
versions do not have this issue.
- In some cases, we continue to use buildin_c(l|t)z(), (e.g. in
src/Common/BitHelpers.h) because the std:: versions only accept
unsigned inputs (and they also check that) and the casting would be
ugly.
(*) https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html
