On 20-04-2020 09:58, Kees Bakker via FreeIPA-users wrote:
> On 20-04-2020 09:09, Florence Blanc-Renaud wrote:
>> On 4/20/20 8:28 AM, Kees Bakker via FreeIPA-users wrote:
>>> Hey,
>>>
>>> I'm looking for advice how to analyse/debug this.
>>>
>>> On one of the masters the dirsrv is unresponsive. It runs, but every
>>> attempt to connect it hangs.
>>>
>>> The command "systemctl status" does not show anything alarming
>>>
>>> ● dirsrv(a)EXAMPLE-COM.service - 389 Directory Server EXAMPLE-COM.
>>> Loaded: loaded (/usr/lib/systemd/system/dirsrv@.service; enabled; vendor
preset: disabled)
>>> Active: active (running) since vr 2020-04-17 13:46:25 CEST; 1h 33min ago
>>> Process: 3123 ExecStartPre=/usr/sbin/ds_systemd_ask_password_acl
/etc/dirsrv/slapd-%i/dse.ldif (code=exited, status=0/SUCCESS)
>>> Main PID: 3134 (ns-slapd)
>>> Status: "slapd started: Ready to process requests"
>>> CGroup: /system.slice/system-dirsrv.slice/dirsrv(a)EXAMPLE-COM.service
>>> └─3134 /usr/sbin/ns-slapd -D /etc/dirsrv/slapd-EXAMPLE-COM -i
/var/run/dirsrv/slapd-EXAMPLE-COM.pid
>>>
>>> apr 17 15:13:54
linge.example.com ns-slapd[3134]: GSSAPI client step 1
>>> apr 17 15:13:54
linge.example.com ns-slapd[3134]: GSSAPI client step 1
>>> apr 17 15:13:54
linge.example.com ns-slapd[3134]: GSSAPI client step 1
>>> apr 17 15:13:54
linge.example.com ns-slapd[3134]: GSSAPI client step 1
>>> apr 17 15:13:54
linge.example.com ns-slapd[3134]: GSSAPI client step 2
>>> apr 17 15:18:54
linge.example.com ns-slapd[3134]: GSSAPI client step 1
>>> apr 17 15:18:54
linge.example.com ns-slapd[3134]: GSSAPI client step 1
>>> apr 17 15:18:55
linge.example.com ns-slapd[3134]: GSSAPI client step 1
>>> apr 17 15:18:55
linge.example.com ns-slapd[3134]: GSSAPI client step 1
>>> apr 17 15:18:55
linge.example.com ns-slapd[3134]: GSSAPI client step 2
>>>
>>> However, an ldapsearch command hangs forever
>>>
>>> [root@rotte ~]# ldapsearch -H
ldaps://linge.example.com -D
uid=keesbtest,cn=users,cn=accounts,dc=example,dc=com -W -LLL -o ldif-wrap=no -b
cn=users,cn=accounts,dc=example,dc=com
'(&(objectClass=person)(memberOf=cn=admins,cn=groups,cn=accounts,dc=example,dc=com))'
uid
>>> Enter LDAP Password:
>>>
>>> Even if I use the socket (ldapi://%2fvar%2frun%2fslapd-EXAMPLE-COM.socket)
the ldapsearch
>>> command hangs.
>>>
>>> "ipactl status" hangs
>>>
>>> "kinit" hangs
>>>
>>>
>> Hi,
>> you can start by having a look at dirsrv error log in
>> /var/log/dirsrv-slapd-YOUR_DOMAIN/errors, and the journal.
>>
>> The FAQ page of 389 also explains a few troubleshooting steps:
>>
http://www.port389.org/docs/389ds/FAQ/faq.html#Troubleshooting
> I did exactly that, look at the "errors" log, but there was no clue, at
least
> not for me. Strange enough it kept running for a few hours and then it
> was hanging again.
>
> I tried the command "ipctl restart", but that was hanging forever.
> However "systemctl restart dirsrv@MY-DOMAIN" was able to restart
> it after several minutes. Meanwhile the sn-slapd process was using 100%
> CPU.
>
> Another remark I want to make. Every ldap connection (ldapsearch, whatever)
> hangs for ever. No timeout, nothing.
>
> When it rains, it pours, they say. There is another master with the same symptom.
> I'm getting nervous now.
>
> Thanks for the Troubleshooting link. I'll have to dive into the deep, I guess.
Could it be a deadlock?
[root@linge ~]# grep -a1 '^#0.*lock' slapd-stacktrace.1587374239.txt
Thread 23 (Thread 0x7ff8ff265700 (LWP 14474)):
#0 0x00007ff929430144 in pthread_rwlock_rdlock () at /lib64/libpthread.so.0
#1 0x00007ff9190cc49c in map_rdlock () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
--
Thread 7 (Thread 0x7ff8f7255700 (LWP 14490)):
#0 0x00007ff929430144 in pthread_rwlock_rdlock () at /lib64/libpthread.so.0
#1 0x00007ff9190cc49c in map_rdlock () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
--
Thread 4 (Thread 0x7ff8f5a52700 (LWP 14493)):
#0 0x00007ff929430144 in pthread_rwlock_rdlock () at /lib64/libpthread.so.0
#1 0x00007ff9190cc49c in map_rdlock () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
--
Thread 2 (Thread 0x7ff92c355700 (LWP 15679)):
#0 0x00007ff92943035e in pthread_rwlock_wrlock () at /lib64/libpthread.so.0
#1 0x00007ff9190b6639 in backend_be_pre_write_cb () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
Without debuginfo the trace of these threads look like this:
Thread 23 (Thread 0x7ff8ff265700 (LWP 14474)):
#0 0x00007ff929430144 in pthread_rwlock_rdlock () at /lib64/libpthread.so.0
#1 0x00007ff9190cc49c in map_rdlock () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
#2 0x00007ff9190b8745 in backend_search_cb () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
#3 0x00007ff92bcd9028 in plugin_call_func () at /usr/lib64/dirsrv/libslapd.so.0
#4 0x00007ff92bcd92e3 in plugin_call_plugins () at /usr/lib64/dirsrv/libslapd.so.0
#5 0x00007ff92bccc0d7 in op_shared_search () at /usr/lib64/dirsrv/libslapd.so.0
#6 0x0000562454427bbe in do_search ()
#7 0x000056245441595a in connection_threadmain ()
#8 0x00007ff929a8cc5b in _pt_root () at /lib64/libnspr4.so
#9 0x00007ff92942ce65 in start_thread () at /lib64/libpthread.so.0
#10 0x00007ff928ad888d in clone () at /lib64/libc.so.6
Thread 7 (Thread 0x7ff8f7255700 (LWP 14490)):
#0 0x00007ff929430144 in pthread_rwlock_rdlock () at /lib64/libpthread.so.0
#1 0x00007ff9190cc49c in map_rdlock () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
#2 0x00007ff9190b8745 in backend_search_cb () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
#3 0x00007ff92bcd9028 in plugin_call_func () at /usr/lib64/dirsrv/libslapd.so.0
#4 0x00007ff92bcd92e3 in plugin_call_plugins () at /usr/lib64/dirsrv/libslapd.so.0
#5 0x00007ff92bccc0d7 in op_shared_search () at /usr/lib64/dirsrv/libslapd.so.0
#6 0x0000562454427bbe in do_search ()
#7 0x000056245441595a in connection_threadmain ()
#8 0x00007ff929a8cc5b in _pt_root () at /lib64/libnspr4.so
#9 0x00007ff92942ce65 in start_thread () at /lib64/libpthread.so.0
#10 0x00007ff928ad888d in clone () at /lib64/libc.so.6
Thread 4 (Thread 0x7ff8f5a52700 (LWP 14493)):
#0 0x00007ff929430144 in pthread_rwlock_rdlock () at /lib64/libpthread.so.0
#1 0x00007ff9190cc49c in map_rdlock () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
#2 0x00007ff9190b8745 in backend_search_cb () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
#3 0x00007ff92bcd9028 in plugin_call_func () at /usr/lib64/dirsrv/libslapd.so.0
#4 0x00007ff92bcd92e3 in plugin_call_plugins () at /usr/lib64/dirsrv/libslapd.so.0
#5 0x00007ff92bccc0d7 in op_shared_search () at /usr/lib64/dirsrv/libslapd.so.0
#6 0x0000562454427bbe in do_search ()
#7 0x000056245441595a in connection_threadmain ()
#8 0x00007ff929a8cc5b in _pt_root () at /lib64/libnspr4.so
#9 0x00007ff92942ce65 in start_thread () at /lib64/libpthread.so.0
#10 0x00007ff928ad888d in clone () at /lib64/libc.so.6
Thread 2 (Thread 0x7ff92c355700 (LWP 15679)):
#0 0x00007ff92943035e in pthread_rwlock_wrlock () at /lib64/libpthread.so.0
#1 0x00007ff9190b6639 in backend_be_pre_write_cb () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
#2 0x00007ff92bcd9028 in plugin_call_func () at /usr/lib64/dirsrv/libslapd.so.0
#3 0x00007ff92bcd92e3 in plugin_call_plugins () at /usr/lib64/dirsrv/libslapd.so.0
#4 0x00007ff91b08ac88 in ldbm_back_delete () at
/usr/lib64/dirsrv/plugins/libback-ldbm.so
#5 0x00007ff92bc89feb in op_shared_delete () at /usr/lib64/dirsrv/libslapd.so.0
#6 0x00007ff92bc8a1c8 in delete_internal_pb () at /usr/lib64/dirsrv/libslapd.so.0
#7 0x00007ff9196f131e in delete_changerecord () at
/usr/lib64/dirsrv/plugins/libretrocl-plugin.so
#8 0x00007ff9196f1605 in changelog_trim_thread_fn () at
/usr/lib64/dirsrv/plugins/libretrocl-plugin.so
#9 0x00007ff929a8cc5b in _pt_root () at /lib64/libnspr4.so
#10 0x00007ff92942ce65 in start_thread () at /lib64/libpthread.so.0
#11 0x00007ff928ad888d in clone () at /lib64/libc.so.6
With the following (stripped) debuginfo you can see that it is hanging while deleting
a changerecord.
Thread 2 (Thread 0x7ff92c355700 (LWP 15679)):
#0 0x00007ff92943035e in pthread_rwlock_wrlock () at /lib64/libpthread.so.0
#1 0x00007ff9190b6639 in backend_be_pre_write_cb () at
/usr/lib64/dirsrv/plugins/schemacompat-plugin.so
#2 0x00007ff92bcd9028 in plugin_call_func (list=0x5624565a3340,
operation=operation@entry=453, pb=pb@entry=0x5624629c28
40, call_one=call_one@entry=0) at ldap/servers/slapd/plugin.c:2028
n = <optimized out>
func = 0x7ff9190b65a0 <backend_be_pre_write_cb>
rc = <optimized out>
return_value = 0
count = 0
#3 0x00007ff92bcd92e3 in plugin_call_list (pb=0x5624629c2840, operation=453,
list=<optimized out>) at ldap/servers/slap
d/plugin.c:1972
p = 0x5624564ea2c0
locked = <optimized out>
plugin_list_number = 3
rc = 0
do_op = <optimized out>
#4 0x00007ff92bcd92e3 in plugin_call_plugins (pb=pb@entry=0x5624629c2840,
whichfunction=whichfunction@entry=453) at lda
p/servers/slapd/plugin.c:442
p = 0x5624564ea2c0
locked = <optimized out>
plugin_list_number = 3
rc = 0
do_op = <optimized out>
#5 0x00007ff91b08ac88 in ldbm_back_delete (pb=0x5624629c2840) at
ldap/servers/slapd/back-ldbm/ldbm_delete.c:373
be = 0x5624564fc000
inst = 0x56245635c680
li = 0x5624562d3a40
e = 0x562462377810
tombstone = 0x0
original_tombstone = 0x0
tmptombstone = 0x0
dn = 0x56245d90fa70 "changenumber=879530,cn=changelog"
txn = {back_txn_txn = 0x562459c2cc60}
parent_txn = 0x0
retval = 0
msg = <optimized out>
errbuf = 0x0
retry_count = <optimized out>
disk_full = 0
parent_found = <optimized out>
ruv_c_init = 0
parent_modify_c = {old_entry = 0x0, new_entry = 0x0, smods = 0x0, attr_encrypt =
0}
ruv_c = {old_entry = 0x0, new_entry = 0x0, smods = 0x0, attr_encrypt = 0}
...