If a resultset is followed by an ERR packet that is not expected
(e.g. server is shutting down), the packet must not be sent to the
client. This allows readwritesplit to replace the failing connection with
a new one thus hiding server shutdowns from clients.
Added range-erase method to mxs::Buffer. This makes it easier to modify
the contents of mxs::Buffer.
The intended use-case for now is to erase unexpected trailing ERR packets
from resultsets.
RWBackend did not expect that a resultset and an unexpected ERR packet
could be stored in the same buffer. This can happen for example if a
server shuts down immediately after the resultset is sent.
With this change, a parenthesized top-level SELECT, such as
"(SELECT f FROM t)" will be fully parsed. Before this change,
the statement was classified as invalid and would thus have
been sent to the master.
With this change also statements like
(SELECT f FROM t1) UNION (SELECT f FROM t2)
will be correctly classified, although only partially parsed.
If a packet with a KILL query was followed with another packet in the same
network buffer, the code wouldn't work as it expected to receive only one
packet at a time.
On RHEL8 the former may give rise to incorrect
error: 'char* strncpy(char*, const char*, size_t)' destination
unchanged after copying no bytes [-Werror=stringop-truncation]
In MaxScale, a "deprecated" parameter is not in use and can be ignored.
Leaving the parameters out of serialized configuration files avoids warning
messages.
The name of the object (i.e. the section name from the configuration
file), is now stored in the configuration object for that object.
That way, more contextual and hence morfe user friendly errors and
warnings can be generated.
If the server (a real one or a service exposed as a server) is
on the same machine as MaxScale, then for performance reasons
a Unix domain socket and not a TCP/IP socket should be used.
