- Selects are picked out using custom parsing, so if a statement is
anything else but a SELECT, the cache will never cause the statement
to be parsed.
- The setting of of the cache parameter `selects` is taken into account.
If it is `assume_cacheable` then the statement will also not be parsed
even if it is a SELECT.
The server state information should be persisted even if a controlled
shutdown is done. This will allow the monitor to retain the server state
information across a restart.
The MySQL monitor stores the server states in a backup file which can be
used to restore the state of the servers even if MaxScale is stoppen in an
uncontrolled fashion.
The hintrouter is now in principle capable of routing requests
to the master or to some slave (in a round robin fashion) based
upon hints set by some earlier filter.
Note that as the router is completely oblivious of transaction
boundaries, using it with transactions and autocommit being off
will not make anyone happy.
Recognizing transaction boundaries using regexes and then pinning
the server until transaction commit would be needed.
The original approach was made for RocksDB where it is beneficial
to keep keys of stuff related to each other close to each other.
However, as RocksDB is no longer the primary focus, it just causes
additional cost to dig out the table names.
The key is a 64-bit integer, but crc32 only gives us a 32-bit one.
We create an other 32-bit value by running crc32 over the same SQL,
using the first crc value as adler.
I think that further reduces the chance for clashes:
uint32_t crc0 = crc32(0, Z_NULL, 0);
uint32_t crc1;
uint32_t crc2;
crc1 = crc32(crc0, "codding", 7) => 1774765869
crc2 = crc32(crc1, "codding", 7) => 1409592046
crc1 = crc32(crc0, "gnu", 3) => 1774765869
crc2 = crc32(crc1, "gnu", 3) => 1213798908
Note that the first value is the same, but the second is not.
When a standalone master server is detected, it should receive the stale
status to prevent it from losing the master status if another server is
started and allow_cluster_recovery is enabled.
The json_stringn function should be used instead of the json_string to
allow null characters as well as non-null terminated strings to be
embedded in the JSON values.
The CDC example Python programs now decode the data as UTF-8 instead of
ASCII.
The libaio is not required by MaxScale so the check for it is no longer
needed.
Updated documentation to match the current requirements to build MaxScale.
Move most of the functions under the filter or session-classes.
Class definitions moved to a header file. General cleanup. Some features
are still incoming.
The filter now accepts (in addition to the old "match" and "server")
parameters of the form "matchN" and "serverN", where N is a decimal
number with two digits, i.e 01, 02, 03 .. 20. When routing queries,
the regural expressions will be tested one by one, and the servers
from the first match will be added as hints. Also, a single "server"-
setting may contain multiple servers separated by ','. The server
names are not verified to be actual servers, this is up to the user.
This is a list of servers, separated by commas. When queried as a
config setting, returns a null-terminated array of SERVER*:s. The
commit includes a serverlist parsing function, which should probably
be used anywhere a similarly formed string is parsed.
For the general case, regex matching simply will not do. The
regex becomes so hairy so it turns write-only, i.e. unmaintainable.
Regex matching is also slower than a handwritten custom parser.
TheBoundaryMatcher is not updated as it is likely it will be removed
altogether. A regex that accepts comments in all relevant places becomes
so hairy it is unmaintainable. It seems that the only working solution
would be to first remove all comments and then perform the regex.
Before checking whether a particular regex matches a statement
we check with one general one whether it at all is possible that
a statement might match.
Since most statements will not be transaction related it makes
sense to first check whether it at all is possible that the
statement might be transaction related.
A class capble of detecting statements that change the transaction
state and autocommit mode. The detection is done using regexes.
There is still some expanding and optimization to be done.
A class capble of detecting statements that change the transaction
state and autocommit mode.
There are still some expansion and optimization to be done.
Transaction boundaries can now be detected using regexes.
All else being equal, it gives a 10% performance improvement
compared to qc-based detection.
In a subsequent change, mysql_client.c will be modified to use
qc_get_trx_type_mask() instead of qc_get_type_mask().
Currently the use of regex matching is turned on using an
environment variable. That will change.
The process and thread initialization/finalization of the query
classifier plugins is handled using the process and thread
initialization/finalization functions in the module object.
However, the top-level query classifier will also need to perform
process and thread initialization when transaction boundaries are
detected using regular expressions.
