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Bug 988559 - deadlock after adding and deleting entries
Summary: deadlock after adding and deleting entries
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: 389-ds-base
Version: 7.0
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: ---
Assignee: Rich Megginson
QA Contact: Sankar Ramalingam
URL:
Whiteboard:
Depends On:
Blocks: 988562
TreeView+ depends on / blocked
 
Reported: 2013-07-25 20:11 UTC by Nathan Kinder
Modified: 2020-09-13 20:40 UTC (History)
2 users (show)

Fixed In Version: 389-ds-base-1.3.1.5-1.el7
Doc Type: Bug Fix
Doc Text:
Cause: Performing many add and delete operations at the same time. Consequence: The server can hang or deadlock. Fix: The entry cache locking needed to be refined. Result: The server does not hang when performing concurrent add and delete operations.
Clone Of:
: 988562 (view as bug list)
Environment:
Last Closed: 2014-06-13 11:43:51 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)
LDIF file that adds and deletes 200 entries (1) (31.87 KB, text/x-ldif)
2013-07-25 20:28 UTC, mreynolds 		no flags Details
LDIF file that adds and deletes 200 entries (2) (32.46 KB, text/x-ldif)
2013-07-25 20:28 UTC, mreynolds 		no flags Details
LDIF file that adds and deletes 200 entries (3) (31.87 KB, text/x-ldif)
2013-07-25 20:29 UTC, mreynolds 		no flags Details
LDIF file that adds and deletes 200 entries (4) (32.46 KB, text/x-ldif)
2013-07-25 20:29 UTC, mreynolds 		no flags Details
LDIF file that adds and deletes 200 entries (5) (32.46 KB, text/x-ldif)
2013-07-25 20:30 UTC, mreynolds 		no flags Details
View All


Links
System ID Private Priority Status Summary Last Updated
Github 389ds 389-ds-base issues 786 0 None None None 2020-09-13 20:40:15 UTC

Description Nathan Kinder 2013-07-25 20:11:50 UTC 
This bug is created as a clone of upstream ticket:
https://fedorahosted.org/389/ticket/47449

If you have multiple clients, each adding and deleting users the server will deadlock.  I created 5 ldif files.  Each ldif file added and then deleted 200 entries.  Using 5 separate ldapmodify's the server will deadlock within a minute or so.

Appears to be an issue with an entry cache lock not being unlocked:

Thread 29 (Thread 0x7f7d16bfd700 (LWP 8337)):
#3  0x0000003b56223fe9 in PR_Lock () from /lib64/libnspr4.so
#4  0x0000003b5622410b in PR_EnterMonitor () from /lib64/libnspr4.so
#5  0x00007f7d29eb19bb in dblayer_lock_backend (be=0x2094160) at ../ds/ldap/servers/slapd/back-ldbm/dblayer.c:3942
#6  0x00007f7d29eb102f in dblayer_txn_begin (be=0x2094160, parent_txn=0x0, txn=0x7f7d16bfa860) at ../ds/ldap/servers/slapd/back-ldbm/dblayer.c:3664
#7  0x00007f7d29eeb814 in ldbm_back_delete (pb=0x7f7d16bfcaa0) at ../ds/ldap/servers/slapd/back-ldbm/ldbm_delete.c:257
#8  0x00007f7d2dc8def4 in op_shared_delete (pb=0x7f7d16bfcaa0) at ../ds/ldap/servers/slapd/delete.c:364
#9  0x00007f7d2dc8d6dd in do_delete (pb=0x7f7d16bfcaa0) at ../ds/ldap/servers/slapd/delete.c:128
#10 0x000000000041578e in connection_dispatch_operation (conn=0x7f7d2464f730, op=0x231ee80, pb=0x7f7d16bfcaa0) at ../ds/ldap/servers/slapd/connection.c:643
#11 0x0000000000417524 in connection_threadmain () at ../ds/ldap/servers/slapd/connection.c:2482

Thread 27 (Thread 0x7f7d157fb700 (LWP 8339)):
#3  0x0000003b56223fe9 in PR_Lock () from /lib64/libnspr4.so
#4  0x0000003b5622410b in PR_EnterMonitor () from /lib64/libnspr4.so
#5  0x00007f7d29eb19bb in dblayer_lock_backend (be=0x2094160) at ../ds/ldap/servers/slapd/back-ldbm/dblayer.c:3942
#6  0x00007f7d29eb102f in dblayer_txn_begin (be=0x2094160, parent_txn=0x0, txn=0x7f7d157f6790) at ../ds/ldap/servers/slapd/back-ldbm/dblayer.c:3664
#7  0x00007f7d29ede3f1 in ldbm_back_add (pb=0x7f7d157faaa0) at ../ds/ldap/servers/slapd/back-ldbm/ldbm_add.c:261
#8  0x00007f7d2dc7dc4b in op_shared_add (pb=0x7f7d157faaa0) at ../ds/ldap/servers/slapd/add.c:735
#9  0x00007f7d2dc7cb96 in do_add (pb=0x7f7d157faaa0) at ../ds/ldap/servers/slapd/add.c:258
#10 0x000000000041576c in connection_dispatch_operation (conn=0x7f7d2464f878, op=0x22ec000, pb=0x7f7d157faaa0) at ../ds/ldap/servers/slapd/connection.c:638
#11 0x0000000000417524 in connection_threadmain () at ../ds/ldap/servers/slapd/connection.c:2482

Thread 15 (Thread 0x7f7d09bf5700 (LWP 8351)):
#0  0x000000377560e054 in __lll_lock_wait () from /lib64/libpthread.so.0
#1  0x00000037756093be in _L_lock_995 () from /lib64/libpthread.so.0
#2  0x0000003775609326 in pthread_mutex_lock () from /lib64/libpthread.so.0
#3  0x0000003b56223fe9 in PR_Lock () from /lib64/libnspr4.so
#4  0x0000003b5622410b in PR_EnterMonitor () from /lib64/libnspr4.so
#5  0x00007f7d29eb19bb in dblayer_lock_backend (be=0x2094160) at ../ds/ldap/servers/slapd/back-ldbm/dblayer.c:3942
#6  0x00007f7d29eb102f in dblayer_txn_begin (be=0x2094160, parent_txn=0x0, txn=0x7f7d09bf0790) at ../ds/ldap/servers/slapd/back-ldbm/dblayer.c:3664
#7  0x00007f7d29ede3f1 in ldbm_back_add (pb=0x7f7d09bf4aa0) at ../ds/ldap/servers/slapd/back-ldbm/ldbm_add.c:261
#8  0x00007f7d2dc7dc4b in op_shared_add (pb=0x7f7d09bf4aa0) at ../ds/ldap/servers/slapd/add.c:735
#9  0x00007f7d2dc7cb96 in do_add (pb=0x7f7d09bf4aa0) at ../ds/ldap/servers/slapd/add.c:258
#10 0x000000000041576c in connection_dispatch_operation (conn=0x7f7d2464f4a0, op=0x232c850, pb=0x7f7d09bf4aa0) at ../ds/ldap/servers/slapd/connection.c:638
#11 0x0000000000417524 in connection_threadmain () at ../ds/ldap/servers/slapd/connection.c:2482


---> this thread is causing the deadlock

#3  0x0000003b56223fe9 in PR_Lock () from /lib64/libnspr4.so
#4  0x0000003b5622410b in PR_EnterMonitor () from /lib64/libnspr4.so
#5  0x00007f7d29ea7169 in cache_lock_entry (cache=0x21130b8, e=0x22f67a0) at ../ds/ldap/servers/slapd/back-ldbm/cache.c:1502
#6  0x00007f7d29ebee77 in find_entry_internal_dn (pb=0x7f7d073f0aa0, be=0x2094160, sdn=0x7f7ca400dec0, lock=1, txn=0x7f7d073ee860, flags=0)
    at ../ds/ldap/servers/slapd/back-ldbm/findentry.c:155
#7  0x00007f7d29ebf446 in find_entry_internal (pb=0x7f7d073f0aa0, be=0x2094160, addr=0x22f4b68, lock=1, txn=0x7f7d073ee860, flags=0)
    at ../ds/ldap/servers/slapd/back-ldbm/findentry.c:293
#8  0x00007f7d29ebf530 in find_entry2modify (pb=0x7f7d073f0aa0, be=0x2094160, addr=0x22f4b68, txn=0x7f7d073ee860)
    at ../ds/ldap/servers/slapd/back-ldbm/findentry.c:324
#9  0x00007f7d29eeb8b4 in ldbm_back_delete (pb=0x7f7d073f0aa0) at ../ds/ldap/servers/slapd/back-ldbm/ldbm_delete.c:273
#10 0x00007f7d2dc8def4 in op_shared_delete (pb=0x7f7d073f0aa0) at ../ds/ldap/servers/slapd/delete.c:364
#11 0x00007f7d2dc8d6dd in do_delete (pb=0x7f7d073f0aa0) at ../ds/ldap/servers/slapd/delete.c:128
#12 0x000000000041578e in connection_dispatch_operation (conn=0x7f7d2464f358, op=0x22f4a90, pb=0x7f7d073f0aa0) at ../ds/ldap/servers/slapd/connection.c:643
#13 0x0000000000417524 in connection_threadmain () at ../ds/ldap/servers/slapd/connection.c:2482
Comment 1 mreynolds 2013-07-25 20:28:15 UTC 
Created attachment 778511 [details]
LDIF file that adds and deletes 200 entries (1)
Comment 2 mreynolds 2013-07-25 20:28:48 UTC 
Created attachment 778512 [details]
LDIF file that adds and deletes 200 entries (2)
Comment 3 mreynolds 2013-07-25 20:29:14 UTC 
Created attachment 778513 [details]
LDIF file that adds and deletes 200 entries (3)
Comment 4 mreynolds 2013-07-25 20:29:43 UTC 
Created attachment 778514 [details]
LDIF file that adds and deletes 200 entries (4)
Comment 5 mreynolds 2013-07-25 20:30:04 UTC 
Created attachment 778515 [details]
LDIF file that adds and deletes 200 entries (5)
Comment 6 mreynolds 2013-07-25 20:30:55 UTC 
Steps to reproduce:

[1]  Create an instance of 389 using "dc=example,dc=com" as the suffix.
[2]  Open 5 terminals, and run 5 ldapmodifys using the supplied ldifs at the same time. Example:

    ldapmodify -D "cn=directory manager" -w password -c -f add1.ldif

[3]  Keep running these ldapmodifys until the server hangs.  Usually happens in less than a minute.
Comment 7 Rich Megginson 2013-10-01 23:27:01 UTC 
moving all ON_QA bugs to MODIFIED in order to add them to the errata (can't add bugs in the ON_QA state to an errata).  When the errata is created, the bugs should be automatically moved back to ON_QA.
Comment 9 Sankar Ramalingam 2014-01-30 12:25:46 UTC 
Followed the steps given in comment #6 and waited for 2 to 3 minutes, but didn't observe any crash. Hence, marking the bug as verified.
Comment 10 Ludek Smid 2014-06-13 11:43:51 UTC 
This request was resolved in Red Hat Enterprise Linux 7.0.

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