Removed the excessive comments in favor of a simplified description. Use
stack-allocated TestConnections and simplify assertions.
The main change is the different SQL used to update the user with the old
password. Direct modification of the `mysql`.`user` database isn't very
neat but it guarantees that the value is updated.
The test should stop MaxScale at the start unless the manual debug flag is
given on the command line. This fixes the connection failure of mxs1719
but reveals a problem with the filter itself.
Due to the skewed accept distribution without SO_REUSEPORT, we use
round-robin assignment of workers for new client connections. This
provides better performance as work is more likely to be evenly
distributed across all threads.
Using a least-busy-worker algorithm would provide a more stable result but
this is not trivially simple to implement. For this reason, the
round-robin based approach was chosen for 2.2.
Parameters that accept whitespace-only values need to have their default
values quoted if they contain only whitespace characters. In 2.2 the
qlafilter is the only module that did not do this.
When a test is checking the status of the nodes, the output is relatively
verbose.
Also changed dropping of users to use the IF EXISTS syntax. This will
remove the errors if the users do not exist.
When a valid target was not found, no error message was logged by the
router. This would cause the "Routing the query failed. Session will be
closed." message to be logged with no explanation as to why the routing
failed.
In addition to the above-mentioned case, no message would be logged if the
target for a COM_STMT_FETCH was not in use.
If the authentication failure was due to a missing database, this extra
information can be logged. This will help cases where users are using
databases that do not exist.
If only one server is used, the amount of requests can be reduced from a
minimum of two to a minimum of one. In most cases this cuts down the
response time in half.
If two or more session commands contain identical buffers, the buffer of
the first session command is shared between the others. This reduces the
amount of memory used to store repeated executions of session commands.
The purging of session command history in readwritesplit was replaced with
session command de-duplication. This was done to prevent problems that
could arise when the order of session commands plays a significant role.
The assertion that was added to RWSplitSession::handle_slave_is_target
failed when delayed_retry was enabled or when slave reconnection
occurred. In 2.3, targets returned by the target selection functions do
not need to be in use but they must be valid connection targets.
All executed session commands were logged in the RWSplitSession
destructor. This is not really necessary and shouldn't have been placed
there in the first place.
When the `optimistic_trx` mode is enabled, all transactions are started on
a slave server. If the client executes a query inside the transaction that
is not of a read-only nature, the transaction is rolled back and replayed
on the master.
The optimistic_trx parameter will control whether transactions are assumed
to be read-only and will be optimistically executed on slave
servers. Currently, the parameter does nothing.
Unconditionally update the previous target on each routed query. This
allows routing to the previous server in case it is needed. One example of
this is a new type of hint that allows routing to the same server where
the previous query was sent.
Also added a minor clarifying comment to the resetting of the
current_query.
Formatted readwritesplit with Astyle. Changed the initialization of
Backend::m_modutil_state to use curly braces to cope with Astyle's lack of
support for curly braces inside parentheses.
Readwritesplit now keeps track of how many read-only and read-write
transactions have been executed. This allows a coarse estimation of how
widely read-only transactions are done even without explicit read-only
transactions being used (i.e. START TRANSACTION READ ONLY).
The characteristics of a transaction can now be tracked by the query
classifier. This allows read-only and read-write transaction statistics to
be calculated.
The tests failed to compile due to invalid use of try_query. For some
reason this wasn't detected by newer compilers.
Also fixed the compilation failure of mxs1713_lots_of_database on CentOS
7.
Also change the following defaults:
- "selects": Was "verify_cacheable", is now "assume_cacheable"
- "cached_data": Was "shared", is now "thread_specific"
Handle the problematic transaction with session command as well as empty
transactions. Also changed test to use wait_for_monitor as well as pass
the value to check as a parameter to the `check` function.
Readwritesplit would crash with the following transaction:
BEGIN;
SET @a = 1; -- This is where it would crash
COMMIT;
When a session command was a part of the transaction, empty queries
(i.e. NULL GWBUFs) would be added to the transaction. If the transaction
were to be replayed, MaxScale would crash when these NULL queries were
executed.
Once the empty responses were fixed, the replaying of the transaction
would fail with a checksum mismatch. This was caused by the wrong order of
processing in RWSplitSession::clientReply. The response processing for
session commands was done after the response processing for replayed
transactions. This would trigger a checksum comparison too early for the
transaction in question.
The test methods that take printf style input now have the printf
attribute. This enables format checks making oversights less likely.
Also fixed any existing errors in the code. Only the one in
test_binlog_fnc.cpp would've had an actual effect.
