The cause of im_daemon_life_cycle.imtest random failures was the following
behaviour of some implementations of LINUX threads: let's suppose that a
process has several threads (in LINUX threads, there is a separate process for
each thread). When the main process gets killed, the parent receives SIGCHLD
before all threads (child processes) die. In other words, the parent receives
SIGCHLD, when its child is not completely dead.
In terms of IM, that means that IM-angel receives SIGCHLD when IM-main is not dead
and still holds some resources. After receiving SIGCHLD, IM-angel restarts
IM-main, but IM-main failed to initialize, because previous instance (copy) of
IM-main still holds server socket (TCP-port).
Another problem here was that IM-angel restarted IM-main only if it was killed
by signal. If it exited with error, IM-angel thought it's intended / graceful
shutdown and exited itself.
So, when the second instance of IM-main failed to initialize, IM-angel thought
it's intended shutdown and quit.
The fix is
1. to change IM-angel so that it restarts IM-main if it exited with error code;
2. to change IM-main so that it returns proper exit code in case of failure.
Corrected spelling in copyright text
Makefile.am:
Don't update the files from BitKeeper
Many files:
Removed "MySQL Finland AB & TCX DataKonsult AB" from copyright header
Adjusted year(s) in copyright header
Many files:
Added GPL copyright text
Removed files:
Docs/Support/colspec-fix.pl
Docs/Support/docbook-fixup.pl
Docs/Support/docbook-prefix.pl
Docs/Support/docbook-split
Docs/Support/make-docbook
Docs/Support/make-makefile
Docs/Support/test-make-manual
Docs/Support/test-make-manual-de
Docs/Support/xwf
tests fail on FreeBSD.
The patch contains of the following:
- make Instance Manager, running in the daemon mode, dump
the pid of angel-process in the special file;
- default value of angel-pid-file-name is 'mysqlmanager.angel.pid';
- if ordinary (IM) pid-file-name is specified in the configuration,
angel-pid-file-name is updated according to the following
rule: extension of the basename of pid-file-name is replaced by
'.angel.pid.
For example:
- pid-file-name: /tmp/im.pid
=> angel-pid-file-name: /tmp/im.angel.pid
- pid-file-name: /tmp/im.txt
=> angel-pid-file-name: /tmp/im.angel.pid
- pid-file-name: /tmp/5.0/im
=> angel-pid-file-name: /tmp/5.0/im.angel.pid
- add support for configuration option to customize angel
pid file name;
- fix test suite to use angel pid to kill Instance Manager
by all means if something went wrong.
Background
----------
The problem is that on some OSes (FreeBSD for one) Instance
Manager does not get SIGTERM, so can not shutdown gracefully.
Test suite wasn't able to cope with it, so this leads to the
mess in test results.
The problem should be split into two:
- fix signal handling;
- fix test suite.
This patch fixes test suite so that it will be able to kill
uncooperative Instance Manager. In order to achieve this,
test suite needs to know PID of IM Angel process.
