when in use.

The problem here is the polling threads in the various acct_gather codes
were detached and could possibly still be polling after the plugin had
been unloaded making a seg fault with a backtrace like this...

#0  0x00007fe7af008c00 in ?? ()
#1  0x00007fe7b1138479 in __nptl_deallocate_tsd () at pthread_create.c:175
#2  0x00007fe7b11398b0 in __nptl_deallocate_tsd () at pthread_create.c:326
#3  start_thread (arg=0x7fe7b1f12700) at pthread_create.c:346
#4  0x00007fe7b0e6fb5d in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

The fix was to make the threads non-detached and join them before calling
a dlclose.

trying to verify the cluster name (which may try to /create/ files or
directories) *before* dropping privs results in a fatal error as
slurmctld tries to create items which ultimately fail.  Moving
this process until after the privs and uid have changed allows
the process to succeed.

Reported by Jon Nelson <jdnelson@dyn.com>

Bug 2728

make it to the slurmctld when using message aggregation.

make sure we handle it correctly when the database comes back up.

    for better robustness.  This cray/select plugin code has
    been modified to remove a possible timing window where two
    aeld pthreads could exist, interfering with each other through
    the global aeld_running variable.

    An additional validity check has been added to the data provided
    to aeld through an alpsc_ev_set_application_info() call.
    If an error is returned from that call, only certain errors
    need the current socket connection closed to aeld and a new
    connection established.  Other error returns will log an
    error message and keep the current session established with
    aeld.

This might possibly be related to bug 2334, but it's a long shot.

slurm.conf instead of all.  If looking for specific addresses use
TopologyParam options No*InAddrAny.

This was broken in 15.08 with the advent of the referenced TopologyParams
the commits 9378f195 and c5312f52 are no longer needed.

Bug 2696

at the same time.

Bug 2683

Turns out making a variable static in a function will make it not safe
when dealing with threads.

With slurm-15.08.10, we're seeing occasional segfaults in slurmstepd. The logs point to the following line: slurm-15.08.10/src/slurmd/slurmstepd/mgr.c:2612

On that line, _get_primary_group() is accessing the results of getpwnam_r():
    *gid = pwd0->pw_gid;

If getpwnam_r() cannot find a matching password record, it will set the result (pwd0) to NULL, but still return 0. When the pointer is accessed, it will cause a segfault.

Checking the result variable (pwd0) to determine success should fix the issue.

Do not attempt to power down a node which has never responded if the
    slurmctld daemon restarts without state.
bug 2698

requesting the RUNNING state.

Backport of commit cca1616b from 16.05

Some systems return EWOULDBLOCK rather than EAGAIN on recv() failure
This is an enhancement to commit af47b4b2