View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000263 | Pgpool-II | Bug | public | 2016-11-19 10:31 | 2016-12-20 11:46 |
| Reporter | tomc797 | Assigned To | t-ishii | ||
| Priority | normal | Severity | crash | Reproducibility | always |
| Status | resolved | Resolution | open | ||
| Platform | AMD64 | OS | Ubuntu | OS Version | 16.10 |
| Product Version | 3.5.4 | ||||
| Target Version | 3.5.5 | ||||
| Summary | 0000263: Segfault when query cache enabled | ||||
| Description | I experience children crashing when the in memory cache is enabled: memory_cache_enabled = on memqcache_method = 'shmem' Once the the cache is disabled, crashing stops. I've experienced this problem with both pgpool2 3.4.8 and 3.5.4 and the packaged versions shipped with ubuntu (3.4.3 and 3.5.3). | ||||
| Steps To Reproduce | Enable caching and let openstack query the databases. | ||||
| Additional Information | A crash produces: [15520.701615] pgpool[9120]: segfault at fffffffffffffff0 ip 000055ffb940c2e3 sp 00007ffc32531668 error 5 in pgpool (deleted)[55ffb93aa000+13b000] Using Yakkety's packaged pgpool2 3.5.3, I've obtained: (gdb) bt #0 pfree (pointer=0x0) at ../../src/utils/mmgr/mcxt.c:709 0000001 0x000055ffb93f0ded in pool_check_and_discard_cache_buffer (oids=0x55ffba21d0a0, num_oids=1) at query_cache/pool_memqcache.c:3084 0000002 pool_handle_query_cache (backend=backend@entry=0x55ffba1ce1e0, query=query@entry=0x55ffba225d30 "INSERT INTO token (id, expires, extra, valid, user_id, trust_id) VALUES ('8eae5f91b861499f96657fc0c8da9d5f', '2016-11-19T02:05:42'::timestamp, '{\"is_domain\": false, \"token_data\": {\"token\": {\"is_domain"..., node=node@entry=0x55ffba2178c0, state=<optimized out>) at query_cache/pool_memqcache.c:3346 0000003 0x000055ffb93e9d31 in ReadyForQuery (frontend=frontend@entry=0x55ffba1cf240, backend=backend@entry=0x55ffba1ce1e0, send_ready=send_ready@entry=1 '\001', cache_commit=cache_commit@entry=1 '\001') at protocol/pool_proto_modules.c:1768 0000004 0x000055ffb93ea115 in ProcessBackendResponse (frontend=frontend@entry=0x55ffba1cf240, backend=backend@entry=0x55ffba1ce1e0, state=state@entry=0x7ffc32533f2c, num_fields=num_fields@entry=0x7ffc32533f2a) at protocol/pool_proto_modules.c:2588 0000005 0x000055ffb93df8de in pool_process_query (frontend=0x55ffba1cf240, backend=0x55ffba1ce1e0, reset_request=reset_request@entry=0) at protocol/pool_process_query.c:304 0000006 0x000055ffb93da046 in do_child (fds=fds@entry=0x55ffba1c8f30) at protocol/child.c:370 0000007 0x000055ffb93b83a7 in fork_a_child (fds=0x55ffba1c8f30, id=135) at main/pgpool_main.c:678 0000008 0x000055ffb93b8d92 in reaper () at main/pgpool_main.c:2263 0000009 0x000055ffb93bd4c6 in PgpoolMain (discard_status=<optimized out>, clear_memcache_oidmaps=<optimized out>) at main/pgpool_main.c:429 0000010 0x000055ffb93b6a51 in main (argc=<optimized out>, argv=0x7ffc325393d8) at main/main.c:310(gdb) frame 1 0000001 0x000055ffb93f0ded in pool_check_and_discard_cache_buffer (oids=0x55ffba21d0a0, num_oids=1) at query_cache/pool_memqcache.c:3084 3084 query_cache/pool_memqcache.c: No such file or directory. (gdb) p soids $1 = (int *) 0x0 (gdb) p *cache->oids $2 = {bufsize = 0, buflen = 0, buf = 0x0} (gdb) p len $3 = 0 (gdb) p num_oids $4 = 1 (gdb) p oids $5 = (int *) 0x55ffba21d0a0 (gdb) p *oids $6 = 42557 I'm attaching two patches that remedy the problem on my system. | ||||
| Tags | query cache | ||||
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A 150 MB core dump can be provided. |
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What is the query exactly? It is omitted in the middle of the query string in the gdb stack trace. |
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I've submitted two versions of the same query in gdb.txt.1. and gdb.txt.2. The query is long, about 8k. |
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I'm attaching a debug log. |
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Your patches look good to me. Will be included in the next minor releases. Thanks! |
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Is 3.6.0 also affected by this bug? If so, what is the timeline for the next minor releases? |
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Yes. The next minor releases will be out by the end of this month. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2016-11-19 10:31 | tomc797 | New Issue | |
| 2016-11-19 10:31 | tomc797 | File Added: check_for_null_buffer.patch | |
| 2016-11-19 10:31 | tomc797 | Tag Attached: query cache | |
| 2016-11-19 10:32 | tomc797 | File Added: pfree_check_for_null_pointer.patch | |
| 2016-11-19 10:33 | tomc797 | Note Added: 0001175 | |
| 2016-11-19 11:10 | t-ishii | Assigned To | => t-ishii |
| 2016-11-19 11:10 | t-ishii | Status | new => assigned |
| 2016-11-19 11:42 | t-ishii | Note Added: 0001176 | |
| 2016-11-19 11:42 | t-ishii | Status | assigned => feedback |
| 2016-11-21 04:03 | tomc797 | File Added: gdb.txt.1 | |
| 2016-11-21 04:03 | tomc797 | File Added: gdb.txt.2 | |
| 2016-11-21 04:05 | tomc797 | Note Added: 0001179 | |
| 2016-11-21 04:05 | tomc797 | Status | feedback => assigned |
| 2016-11-22 03:26 | tomc797 | File Added: shortened.log | |
| 2016-11-22 03:26 | tomc797 | Note Added: 0001185 | |
| 2016-12-06 10:41 | t-ishii | Note Added: 0001203 | |
| 2016-12-09 19:28 | niekb | Note Added: 0001220 | |
| 2016-12-20 11:45 | t-ishii | Note Added: 0001237 | |
| 2016-12-20 11:46 | t-ishii | Target Version | => 3.5.5 |
| 2016-12-20 11:46 | t-ishii | Status | assigned => resolved |
