This commit introduces the plumbing support for obtaining
classification information of a statement using the REST-API.
It introduces a URL like
/v1/maxscale/query_classifier/classify?sql=SELECT+1
that in the response will return a JSON object with the
information. Subsequent commits will provide the actual
information.
Even though directly closing the socket is not very neat in the
architectural sense of things, it allows the best of both worlds: the
socket is instantly closed and is open for reuse while the listener struct
is still available as a reference.
This change needs to be revised when the listeners are refactored into
separate objects.
Updated documentation to reflect the change in behavior.
If a listener is defined in a static configuration file, it can now be
destroyed at runtime. If MaxScale is restarted, the listener will be
created again unless the configuration file is modified.
The cache size now refers to the total memory used by the cache instead of
the per thread limit. This makes it easier to use as well as more
predictable by removing the dependency on the number of worker threads.
The admin files are now created with 640 permissions and automatically
created directories now properly set the permissions for the group as
well. All files and directories created by avrorouter and binlogrouter
also now correctly limit the read and write permissions only to the owner
and the group.
If a 10.2.11 or older server without a grant on all mysql tables is found,
the authenticator now falls back to the 10.1 behavior that uses subqueries
instead of CTEs. This is a more user friendly way of working around
MDEV-13453 that causes the problem as all functionality except the support
for composite roles is retained.
If the password field in mysql.user is empty, it is possible that the
actual password is stored in the authentication_string field. Most of the
time this happens due to MDEV-16774 which causes the password to be stored
in the authentication_string field.
Also added a test case that verifies the problem and that it is fixed by
this commit.
Instead of looking at the server version, the actual error message should
be inspected. This guarantees that the correct error message is logged
even with custom builds.
The intention was to send the lowest backend version string automatically
to the client instead of the default handshake version. This did not work
as the service version string was used instead of the server version.
When a DCB is removed and added more than once with poll_add_dcb and
poll_remove_dcb, the code previously chose a different thread each time
the DCB was added. This violated the assumption is that all DCBs are local
to a single worker.
The callbacks iterated over all threads when only the local ones must be
iterated. This prevents a deadlock from occurring when multiple threads
start throttling at the same time.
Also fixed the gwbuf_append debug assertion.
When a connection to a server is lost and the session command history is
disabled, the session will continue as long as at least one connection is
open. Previously the open connection calculation used the same code that
was used when a new session was created which only inspected the
configured server count instead of the actual open connection count.
Created the <maxbase/format.hh> header that contains various helper
functions for formatting values into human readable forms. Currently only
binary to human readable size conversion is implemented.
Drop the requirement that GTID based replication is used for
the BinLog Galera "failover" mechanism. There is no reason for
that restriction; it works just as well with file+position based
replication.
The table creation was not detected as the function used to extract the
table name did not return the fully qualified names. Even if it did return
a fully qualified name, it wouldn't have been correctly processed.
The setting didn't work because the code updated a status flag which
would be overwritten before being read. Also, promotion code now checks
that the server is not in maintenance.
The redirection method checks if a slave connection to the redirection
target already exists. If so, the connection is not modified. Also, failover
better detects duplicate connections during promotion.
When a read-only transaction fails due to a connection error, no message
would be logged. Also added an info level message for the case when a
backend connection would get closed before the session is in the correct
state and a debug assertion that the router session should never be closed
when the handleError method is called.
The removing and slave status updating is now separated to a function.
As the MariaDBServer object now contains the updated slave connections,
keeping track of removed connections is no longer required.
The two cases are now separated. In switchover, the promotion and
demotion targets can swap connections between each other without worry.
In failover, the two connection lists must be merged semi-intelligently.
The slave connections of the two servers are now saved to the operation
descriptor object at the start of the operation. This allows slave status
updating during the operation.
