The configuration doesn't need to be contained in shared pointer as each
session holds its own version of it. This removes most of the overhead in
configuration reloading. The only thing that's left is any overhead added
by the use of thread-local storage.
The function has use outside of the monitors as it makes execution of
worker tasks much more convenient. Currently, this change only moves the
code and takes it into use: there should be no functional changes.
Uses mostly the status functions for reading the flags. Strickly
speaking this breaks the REST API since in some cases (status combinations)
the printed string is different from what was printed before.
The signal handler no longer acquires the service list lock which removes
a number of deadlock possibilities from the shutdown process. Instead, a
global shutdown flag is set that serves the same purpose as the individual
service shutdown flags did.
get_shard_target had become little bloated with the recent changes so
some routing cases were moved to their own functions. Also removed
some code that was not needed.
Replaced the previous RESULTSET with the new implementation. As the new
ResultSet doesn't have a JSON streaming capability, the MaxInfo JSON
interface has been removed. This should not be a big problem as the REST
API offers the same information in a more secure and structured way.
The monitor can now differentiate between slaves with a running
series of slave connections to the master from slaves with broken
links. Both still get the SERVER_SLAVE-flag if 'detect_stale_slave'
is on.
Also, relay servers must be running.
Comparing two fixed std::strings would have equal C strings but comparing
with operator== they would be different. This was a result of the string
modification done by fix_object_name.
Converted the internal header into a C++ header, added std::string
overload and fixed use of the function.
By using the worker local data mechanism, data can be efficiently cached
on the local worker. This avoids all synchronization on reads and only
requires synchronization on a configuration update.
As an additional observation, the testing of std::mutex and SPINLOCK shows
that std::mutex far outperforms the MaxScale SPINLOCK even on
non-conflicting workloads.
The filter implementation is now fully hidden. Also converted it to a C++
struct allocated with new and stored the filters in a global list instead
of embedding the list in the object itself.
The causal read queries were performed also when the target server was the
master. The extra functionality of the causal reads is only needed on
slaves.
Adjusted the test case to require GTID replication.
The configuration used the wrong parameter name. The test also did not
explicitly enable tracking of the last_gtid variable which caused it to
fail if it wasn't already on.
The test failed because router instances are now created when the service
is allocated. In addition to this, a debug assertion was hit when a
service was freed if the router instance creation failed.
As all connections should be accepted via dcb_accept, it is the optimal
place to calculate how many open client connections per service there
are. The decrementation should be done when the session is closed instead
of when the call to dcb_close for the client DCB is done. This allows the
client count to be the absolute reference count that sessions have to a
service.
The current client count is a duplicate counter that should match the
n_current value in SERVICE_STATS. The former does differ from the latter
in that it does the incrementation when the client DCB is accepted instead
of when the session is created.
Add support for binary protocol prepared statements for schemarouter.
This implementation doesn't yet attempt to handle all the edge cases.
Prepared statements are routed to the server that contains the affected
tables, the internal id from the server is then mapped to the session
command id that is inceremented for each prepared statement. This unique
session command id is returned to the client because internal id given
by server might be same around different servers and this way it is
possible to keep track of them and route them to the right servers when
executed.
When the query queue does not contain a complete packet
(i.e. modutil_get_next_MySQL_packet return NULL), an informative dump of
how many bytes and what is stored is logged.
The LocalClient micro-client required a reference to the session that was
valid at construction time. This is the reason why the previous
implementation used dcb_foreach to first gather the targets and then
execute queries on them. By replacing this reference with pointers to the
raw data it requires, we lift the requirement of the orignating session
being alive at construction time.
Now that the LocalClient no longer holds a reference to the session, the
killing of the connection does not have to be done on the same thread that
started the process. This prevents the deadlock that occurred when
concurrect dcb_foreach calls were made.
Replaced the unused dcb_foreach_parallel with a version of dcb_foreach
that allows iteration of DCBs local to this worker. The dcb_foreach_local
is the basis upon which all DCB access outside of administrative tasks
should be built on.
This change will introduce a regression in functionality: The client will
no longer receive an error if no connections match the KILL query
criteria. This is done to avoid having to synchronize the workers after
they have performed the killing of their own connections.
If a client is executing a COM_CHANGE_USER command and the
reauthentication of the client fails, no error message would be logged
about the failure of the reauthentication process and only a routing
failure message would be logged.
If auto_failover is disabled and an alternative master exists, the
monitor will swap the master. This may break replication, but the
situation requires that the dba has set up a cluster with multiple
masters.
MariaDBMonitor diagnostics printing is unsafe as some of the read
fields are arrays. To be on the safe side, the fields are now read
in the monitor worker thread.
Since diagnostics must work even for stopped monitors, a worker task
is used. In practice, it usually runs when the monitor is sleeping.
Because of monitor changes, the test had wrong assumptions.
Renamed the test and updated it to use MaxCtrl for some queries.
Also, changed the type of the cycle container in the monitor to an
ordered map so that results are predictable.
The result collection now covers more cases, including the use of
COM_CHANGE_USER. The addition of COM_STMT_EXECUTE to the list of commands
that generate result set responses is needed in order for the code to take
the correct branch.
With the removal of the old session command implementation, the code that
used it can be removed or replaced with newer constructs. As a result, the
backend protocol no longer does any session command processing.
The three buffer types, GWBUF_TYPE_SESCMD_RESPONSE,
GWBUF_TYPE_RESPONSE_END and GWBUF_TYPE_SESCMD as well as their related
macros are no longer used and can be removed.
The test cases allocated servers in a way that doesn't comfortably suit
the way the servers are now allocated. Adding a helper C++ class to load
module defaults makes it easier to do explicit server initialization in
tests.
The binlogrouter was also fixed in this commit as it uses servers much
like a test would use.
The configuration system that modules use allows the SSL parameter
validation to be simplified. It should also provide more consistent error
messages for similar types of errors.
The SSL_LISTENER initialization is now done in one step. There was no good
reason to do it in two separate steps for listeners but in one step for
servers.
The `ssl` parameter now also accepts boolean values. As the parameter
behaves like a boolean and looks like a boolean, it ought to be a
boolean. It still accepts the custom `required` and `disabled` values
simply for backwards compatibility.
Also added the missing freeing functions for the SSL_LISTENER type. This
prevents failed SSL_LISTENER creations from leaking memory.
