The `master_reconnection` parameter now controls both the reconnection of
the master server as well as the migration of the master server to another
server. Although these two cases appear to be different, the end result
from readwritesplit's point of view is the same and are thus controlled
with the same parameter.
The RWBackend class now resets its internal state when it is closed. This
allows readwritesplit to handle the case when a result was expected from
the master but the master died before the result was returned. The same
code should also handle slave connection failures mid-result, allowing
Backend reuse.
Added a test case that verifies the new functionality when combined with
`master_failure_mode=error_on_write`.
Provides a clearer separation between what deals with query
classification and what deals with query routing.
Functions have only been moved. No other cleanup has been
done.
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.
* 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
The result collection did not reset properly when a non-resultset was
returned for a request. As collected result need to be distinguishable
from single packet responses, a new buffer type was added.
The new buffer type is used by readwritesplit which uses result collection
for preparation of prepared statements.
Moved the current command tracking to the RWBackend class as the command
tracked by the protocol is can change before a response to the executed
command is received.
Removed a false debug assertion in the mxs_mysql_extract_ps_response
function that was triggered when a very large prepared statement response
was processed in multiple parts.
Inlined the getter/setter type functions that are often used. Profiling
shows that inlining the RWBackend get/set functions for the reply state
manipulation reduces the relative cost of the function to acceptable
levels. Inlining the Backend state function did not have as large an
effect but it appears contribute a slight performance boost.
The result processing code did unnecessary work to confirm that the result
buffers are contiguous. The code also assumed that multiple packets can be
routed at the same time when in fact only one contiguous result packet is
returned at a time.
By assuming that the buffers are contiguous and contain only one packet,
most of the copying and buffer manipulation can be avoided.
The EOF packet calculation function in modutil.cc didn't handle the case
where the payload exceeded maximum packet size and could mistake binary
data for a ERR packet.
The state of a multi-packet payload is now exposed by the
modutil_count_signal_packets function. This allows proper handling of
large multi-packet payloads.
Added minor improvements to mxs1110_16mb to handle testing of this change.
The connections for a router session can now be done without a constructed
router session. This simplifies the creation of new router session by
removing the need to handle memory allocations.
Readwritesplit router sessions are now created in the static `create`
function which handles the actual creation of the connections and
allocation of the session itself.
Moved the initialization of the router session's member variables into the
constructor. Changed two functions that calculated server counts into the
router instance as they don't relate to a particular session.
