The output of `show threads` could have a negative historic thread load
average that could be explained by the overflow of the signed 32-bit
integer used to count the number of samples.
The time that each thread started to process an event for a DCB used an
old value that is no longer used. Updating this to DCB::last_read retains
the 2.0 behavior.
Previously, if the list contained servers that were not monitored by
the monitor yet were valid servers, an error value would be returned
and the monitor failed to start.
With this update, the non-monitored servers are simply ignored when
forming the final list.
Also, added printing of the list to diagnostics.
Now the users will be reloaded at most once during each
USERS_REFRESH_TIME period. Earlier they could be reloaded at
at most USERS_REFRESH_MAX_PER_TIME times, which in practice meant
that with repeated unauthorized login attempts they were reloaded
N times in rapid succession, without the situation being likely to
change in between.
The error regarding the refresh rate having been exceeded
error: [RWSplit] Refresh rate limit exceeded ...
has been turned into a warning. Further, the warning will be
logged at most once per refresh period that currently is 30s.
This is used only in case of everything else fails and this lookup
is not unlikely to fail if the client comes from some machine on
an internal network.
If the master is replicating from an external master, the monitor will save the
host:port of the external server. During demotion, the old master stops the external
replication while the new master begins it. Also, any commands that would add
to gtid have to be omitted when an external master is in play.
When a BEGIN statement is prepared using the binary protocol, it returns a
single OK packet. Due to a bug in the code that deals with multi-statement
results and EOF packets, the response was never sent to the client.
Also added back the error messages of failed session commands to the INFO
level. This way it's still possible to see why a session command fails but
the log isn't flooded by them in normal usage.
The tests are now built by default. This should make it easier for users
to verify that they have a working MaxScale.
Also made the building of test_parse_kill conditional like the rest of the
tests.
When four servers (A, B, C and E where E and A replicate from each other
and A is the master for B and C) form a cluster and only three of them (A,
B and C) are configured into MaxScale, a failover operation from A to B
(making B the current master) and a restart of A causes B to lose its
master status.
The following diagram illustrates the state of the cluster at the end of
the process described above.
+----------------------+
| +---+ |
+------------+ B <-+ |
+-v-+ | +---+ | |
| E | | | |
+-^-+ | +---+ +-+-+ |
+------+ A | | C | |
| +---+ +---+ |
| |
+----------------------+
The external server E was not correctly ignored in the replication
topology generation causing both A and B to be seen as the lowest slave
nodes in the tree. From a theoretical point of view this is the correct
interpretation as there are two distinct trees and neither of them
contains any true masters.
In practice, MaxScale should treat any servers that replicate from an
external master as root level master nodes. Doing this guarantees that they
are labeled as masters if they have slaves replicating from them.
The responses of slaves that arrived before the master were always
compared to the empty value of 0x00. If the slave connection replied after
the master, the comparison was correct.
This commit introduces a map of slaves and their responses that
are handled once the master's response arrives.
Removed false error message about failed session commands. An error in
response to a session command is a perfectly valid result.
Also added the explicit commands that the master and slave return to the
warning that is logged when the results differ.
The debug assertion wasn't well placed as it is perfectly possible that a
master connnection exists but it is not in use. This can be further
checked by asserting that the master is indeed closed and not in use.
Moved the original debug assertion into a separate branch that should
catch any errors in the routing logic.
When detect_standalone_master is enabled, the root_master variable was not
updated after the master was changed by the standalone server detection
mechanism. This caused debug assertions to fire in addition to possibly
causing some of the ignore_external_masters logic to break.
"servers_no_promotion" is a comma-separated list of servers
which cannot be chosen when selecting a new master during failover
(auto or manual), or when automatically selecting a new master
for switchover (currently disabled).
The servers in the list are redirected normally and can be promoted
by switchover when manually selecting a new master.
If the API versions do not match, MaxScale will treat this as an
error. The API versioning would allow backwards compatible changes but the
functionality to handle that is not implemented in MaxScale.
Updated API versions based on changes done to module APIs in 2.2.
With the flag --debug=enable-statement-logging it is now possible
to instruct MaxScale to log all SQL statements it sends to the
servers.
The format of the logged string looks like:
notice : SQL(127.0.0.1): 0, "SELECT ..."
First the fixed string "SQL", followed by the server address in
parenthesis followed by the actual return value of mysql_query(),
followed by the statement itself.
The "SQL" string makes the lines easy to grep for and having the
return value before the statement makes it easier to spot since
the length of the return value string does not wary much, but the
length of the statements do wary a lot.
The Master status now prevents Slave status from being assigned to a
server. In practice this simply means that the master will not have both
the Master and Slave status bits.
Since a shutdown message will now be sent via the regular epoll route,
there is no need to regularily wake up from epoll in order to check
whether shutdown has been initiated, but we can simply wait in epoll_wait
until told to wake up.
* MXS-199: Support Causal Read in Read Write Splitting
* move most causal read logic into rwsplit router and get server type from monitor
* misc fix: remove new line
* refactor, move config to right place, replace ltrim with gwbuf_consume
* refacter a little for previous commit
* fix code style
In some cases you might want to use a specific address/interface
when connecting to a server instead of the default one. With the
global parameter 'local_address' it can now be specified which
address to use.
By always starting the session shutdown process by stopping the client
DCB, the manipulation of the session state can be removed from the backend
protocol modules and replaced with a fake hangup event.
Delivering this event via the core allows the actual dcb_close call on the
client DCB to be done only when the client DCB is being handled by a
worker.
Directly closing the client DCB in the backend protocol modules is not
correct anymore as the state of the session doesn't change when the client
DCB is closed. By propagating the shutdown of the session with a fake
hangup to the client DCB, the closing of the DCB is done only once.
Added debug assertions that make sure all DCBs are closed only
once. Removed redundant code in the backend protocol error handling code.
The token skipping function did not check for a period or an opening
parenthesis when parsing the test. Also fixed a debug assertion when only
NULL values were inserted.
In debug mode, when scanning the server id from a string, check that resulting
number is 32bit. Also, when querying the server id, query the global version.
Now, if a super user modifies the server id the monitor will notice it.
Server id:s in gtid:s are handled similarly.
When a double close is detected in a debug build, a debug assertion is
triggered. This will generate a core dump which should help investigate
the double close.
As chages to the transaction state are detected by the protocol level
mini-parser, there's no need to fully classify queries inside read-only
transactions. This should be a good performance boost for loads that
heavily use read-only transactions.
