Now that the exit handlers work correctly, the output of `maxscale
--version` no longer consists of a single line but multiple lines in both
stdout and stderr. Removing the printing to stderr guarantees that the
correct output is produced.
The runtime configuration of a MaxScale can now be exported to a single
file. This allows modifications made via runtime configuration commands to
be "committed" for later use.
Backported the minimal set of changes required to build 2.1 with GCC
8. The format-truncation and format-overflow warnings are disabled instead
of fixed in 2.1 to remove duplication of effort that was already done in
2.2 (the commit doesn't cherry-pick cleanly).
From a practical perspective it makes no relevant difference
whether you have to add an entry to the config file and restart
maxscale or if you have to restart maxscale and provide a specific
command line, so better to provide just either possiblity.
More important would be to provide a way for turning this feature
on and off at runtime.
With the configuration entry
dump_last_statements=[never|on_close|on_error]
you can now specify when and if to dump the last statements
of of a session.
With the configuration entry
retain_last_statements=<unsigned>
or the debug flag '--debug=retain-last-statements=<unsigned>',
MaxScale will store the specified number of last statements
for each session. By calling
session_dump_statements(session);
MaxScale will dump the last statements as NOTICE messages.
For debugging purposes.
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.
According to customer reports collecting the statistics has a significant
impact on the performance. As we don't need that information we can just
as well turn off that.
Further, since maxscale-common now links to the sqlite3-library, no
module needs to do that explicitly.
The internal header directory conflicted with in-source builds causing a
build failure. This is fixed by renaming the internal header directory to
something other than maxscale.
The renaming pointed out a few problems in a couple of source files that
appeared to include internal headers when the headers were in fact public
headers.
Fixed maxctrl in-source builds by making the copying of the sources
optional.
With "--daemon" or "-n" MaxScale can now be told to run in daemon
mode, that is, it forks and the parent exits. This is the default
behaviour, but a flag to this effect is needed if the default
behaviour is changed.
MaxScale now refuses to run as root. However, it is possible to
start MaxScale as root, as long as a user to run MaxScale as is
provided as a command line argument.
It is possible to run as root by invoking MaxScale as root and
by specifying the MaxScale user to be root.
When pre-parsing the configuration file, the existence of environment
variables is only done for the [maxscale] section. For other sections
a nicer error message is obtained if the comlplaint is made when the
configuration file is actually loaded.
Mechanism for providing custom error message from the pre-parsing
function added.
With this variables set to true, if $VAR is used as a value in the
configuration file, then `$VAR` will be replaced with the value of
the environment variable VAR.
The GLIBC backtrace functionality doesn't generate file names and line
numbers in the generated stacktrace. This can to be done manually by
executing a set of system commands.
Conceptually doing non-signal-safe operations in a signal handler is very
wrong but as stacktraces are only printed when something has gone horribly
wrong, there is no real need to worry about making things worse.
As a safeguard for fatal errors while the stacktrace is being generated,
it is first dumped into the standard error output of the process. This
will function even if malloc is corrupted.
The GLIBC backtrace functionality doesn't generate file names and line
numbers in the generated stacktrace. This can to be done manually by
executing a set of system commands.
Conceptually doing non-signal-safe operations in a signal handler is very
wrong but as stacktraces are only printed when something has gone horribly
wrong, there is no real need to worry about making things worse.
As a safeguard for fatal errors while the stacktrace is being generated,
it is first dumped into the standard error output of the process. This
will function even if malloc is corrupted.
The stack traces weren't logged as the LOG_ALERT priority wasn't enabled
by default. As an alert is intended to be something that must leave a
trace somewhere, and as such, it must not be possible to disable it. For
this reason, it is acceptable to always log the message if the priority is
LOG_ALERT.
Added the -rdynamic linker flag so that all symbols are exported when
linking MaxScale.
As the stack trace is printed in a signal handler, the first attempt
should be to print the stack trace to the standard output. This way the
output is printed before an attempt to use malloc is made when it is
logged to the logfile.
The `passive` parameter can be given in the configuration file or on the
command line. It is displayed in the diagnostic output and changes to it
are persisted.
The variable itself does nothing.
The original process should use _exit if the forking of the child process
is successful. This makes sure that the exit handlers are called only when
the daemon process exits.
The workers need to be destroyed only after services have been
to ensure that they are around in case the destruction of services
involves the closing of dcbs.
The default interface for the admin interface is the IPv6 address '::'
which corresponds to the IPv4 address '0.0.0.0'. If the system doesn't
support IPv6, then an attempt to bind on IPv4 should be made.
Added a debug option that allows stdout and stderr to be redirected to a
file. This helps with the use of ASAN which prints all of its findings to
stderr.
