The qlafilter now has an option to log all messages to a single
file instead of session-specific files. Session ids are printed
to the beginning of the line when using this mode. Documentation
updated to match. Also, added an option to flush after every
write.
The monitors and services didn't use TLS when they connected to the
backend servers. Since there has been no proof of instability, TLS should
be enabled.
When persistent connections were used, it was possible that the injection
of COM_CHANGE_USER statements caused a crash when a DCB in the wrong state
was accessed.
For MySQL protocol modules, the `data` member of the client DCB points to
the shared session data, a MYSQL_session struct, but for sessions in the
persistent pool, it points to NULL. The boolean, `was_persistent`, tells
whether a DCB was just taken from the pool or it has been in use.
The `was_persistent` status wasn't properly reset for connections that
were put into the pool which caused a COM_CHANGE_USER statement to be
injected for stale connections in the pool which caused a crash when the
NULL `data` member was accessed.
Previously the session_id incrementation was done after creating
filters, giving the filters a constant zero value for session_id.
Now the incrementation happens before filter creation.
The Resources document lists all currently known resources and will be converted
to a list of separate resource documents once the individual resource documents
are done. The Headers and Response Codes document contains a list of request and
response headers and the HTTP return codes. This is a work in progress and will
be expanded upon.
Added initial versions of the filter, monitor, session and user resource
documents. These provide information about various parts of MaxScale and
allow interaction.
All PATCH operations expect a JSON Patch type document in the request
body. Examples modified accordingly.
Add MaxScale resource document which describes the resources that give the
global configuration options and show statistics.
The resources that link to other resources provide values as a list of
relative links. This reduces the amount of sent data when the client
doesn't require all parts of the resource.
Since the updating is not yet implement, it should be stated that the update API
will most likely be modified at some point.
The module resource is similar to `maxadmin show modules` and the log
resource contains status information about logs. The log resource also has
an "action" resource at `/maxscale/logs/flush` which flushes logs to disk
and rotates them.
Added start and stop entry points for services and monitors. Also added
missing service parameters to the list of parameters that can be updated.
The documentation lists listeners as a sub-resource of the
service. This allows the listeners of a particular service to be queried.
This allows safer lock-free reads to be done on lists that never shrink in
size. The main use-case for this is to allow servers to be added to a
service without locking the service each time a new session is created.
Synchronizing the memory before adding new components into a list
guarantees that if a session reads from the list and sees the new list
item, the memory pointed by the item is valid.
Function is no longer used and it was quite unoptimal, so now
removed.
qc_get_prepare_name, qc_get_prepare_operation and qc_get_field_info
that were missing from qc_dummy added at the same time.
A HAVING clause can only refer to names that already have been mentioned
or if "SELECT *" is used. Either way, the HAVING names need not be separately
collected.
We now collect more information about a particular field and
then, if necessary, copy the data over into affected_fields if
someone is interested in that.
The comparison program is extended as well, but qc_get_fields_infos()
is not tested, because qc_mysqlembedded does not implement this yet.
The error logging is now more detailed and tells why the connection is
being closed. This should help the user figure out what is happening when
write fails and the connection is closed.
Some of the master server status checks didn't check whether the server
was actually running. The macros in server.h should always be used instead
of manually inspecting the server status.
If a readwritesplit session is active, it should never connect to a new
master. This will lead to unexpected results as the session states aren't
consistent.
If an illegal DCB close is done with a backend DCB, it will log the server
where it was connected. This allows us to know whether the DCB was
connected to a master or a slave.
Added more debug assertions to readwritesplit code. The DCBs should never
enter the DCB_STATE_DISCONNECTED.
Removed useless debug log messages. The messages usually just flood the
logs with no use to the developers.
The filter can detect SERVER_MORE_RESULTS_EXIST which means the server
is sending more result sets: example:
DROP PROCEDURE IF EXISTS multi;
DELIMITER $$
CREATE PROCEDURE multi() BEGIN
SELECT 1;
SELECT id FROM t2 limit 40;
set @a=4;
SELECT 2;
END$$
DELIMITER ;
MySQL> call multi()
The check for the success of the configuration file always resulted in a
successful return value even if the loading failed.
In addition to this, a log message referred to the active configuration
when the active configuration was set only after the processing was
complete. Since configuration failures are always fatal, there's no harm
in preemptively setting the active configuration to the one currently
being processed.
A debug assertion failed due to a NULL buffer but a non-zero packet
length. This was caused by a missing reset of the packet length after
freeing the buffers.
If a Galera node has a nonpositive priority, the node will never be chosen
as the master. This gives the user more control over how the master is
chosen.
Some error messages were logged at INFO level and some had conditions that
prevent the logging. Removed these restrictions that an error situation is
always logged.
The luafilter didn't use a format string with dcb_printf which can lead to
unexpected results if the returned string contains printf special
characters.
If a master_failure_mode was set to error_on_write, a reconnection to the
old master would happen after the following events:
- Master server fails and the connection is closed
- The master server recovers
- A slave fails and the connection is closed
- A replacement for the slave is searched
If these events took place, the master would be taken back into use with
an inconsistent session state.
This function returns more detailed information about the fields
of a statement. Supersedes qc_get_affected_fields() that will
be deprecated and removed.
Note that this function now introduced new kind of behaviour; the
returned data belongs to the GWBUF and remains valid for as long as
the GWBUF is alive. That means that unnecessary copying need not
be done.
