View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000094 | Pgpool-II | Bug | public | 2014-02-08 06:13 | 2015-01-08 16:13 |
| Reporter | hootfrancois | Assigned To | nagata | ||
| Priority | urgent | Severity | crash | Reproducibility | always |
| Status | closed | Resolution | fixed | ||
| Platform | Linux | OS | Ubuntu | OS Version | 12.04 LTS |
| Summary | 0000094: Segfaults when using ORDER in parallel mode | ||||
| Description | We're using parallel mode, which works great for most things, but it chokes when we try to use ORDER in a SELECT query. The child process reports a segfault and dies. kernel: [154998.501807] pgpool[14952]: segfault at 10 ip 00000000004271e9 sp 00007fff1974d170 error 4 in pgpool[400000+109000] | ||||
| Steps To Reproduce | - Make sure hstore is available CREATE EXTENSION hstore; - Create a table (on 2 or more nodes) CREATE TABLE autocomplete ( id character varying(100) NOT NULL, extra_data hstore, username character varying(254), member_id bigint ); - Run a SQL query through pgPool SELECT * FROM autocomplete ORDER BY member_id | ||||
| Additional Information | Here's a backtrace. #0 0x0000000000437cd9 in rewrite_query_stmt (node=0x11349b8, frontend=0x111edf0, backend=0x111d310, message=0x724da0) at parallel_query/pool_rewrite_query.c:385 0000001 0x0000000000438571 in pool_do_parallel_query (frontend=0x111edf0, backend=0x111d310, node=0x11349b8, parallel=0x7fffaf69f608 "\001", string=0x7fffaf69f5f0, len=0x7fffaf69f5fc) at parallel_query/pool_rewrite_query.c:694 0000002 0x0000000000427b37 in SimpleQuery (frontend=0x111edf0, backend=0x111d310, len=47, contents=0x111d190 "SELECT * FROM autocomplete ORDER BY member_id;") at protocol/pool_proto_modules.c:278 0000003 0x000000000042cde4 in ProcessFrontendResponse (frontend=0x111edf0, backend=0x111d310) at protocol/pool_proto_modules.c:2483 0000004 0x0000000000421ebd in read_packets_and_process (frontend=<optimized out>, backend=0x111d310, reset_request=0, state=0x7fffaf69fd14, num_fields=0x7fffaf69fd1c, cont=0x7fffaf69fd1f "\001@Er") at protocol/pool_process_query.c:4966 0000005 0x0000000000422419 in pool_process_query (frontend=0x111edf0, backend=0x111d310, reset_request=0) at protocol/pool_process_query.c:260 0000006 0x000000000041e202 in do_child (unix_fd=4, inet_fd=<optimized out>) at protocol/child.c:374 0000007 0x0000000000407edf in fork_a_child (unix_fd=4, inet_fd=5, id=0) at main/main.c:1227 0000008 0x000000000040861a in reaper () at main/main.c:2446 0000009 reaper () at main/main.c:2358 0000010 0x0000000000406bab in main (argc=<optimized out>, argv=<optimized out>) at main/main.c:684 | ||||
| Tags | No tags attached. | ||||
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The same thing happens when I use LIMIT instead of ORDER. |
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And COUNT(*) |
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I figured out what the cause of these segfaults are. I had configured the parallel processing's host as '' because I wanted it to use a socket instead of TCP as per the documentation. It did work because INSERT queries would save data on the right backend but the log had all sorts of errors in it. I changed the host to 'localhost' and the problem went away. You may want to investigate what's going on there and gracefully handle the issue. Thank you! :) |
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Thanks for your reporting. I fixed this. When system_db_hostname was empty string, initialization of connection to system DB failed, and this caused the segfault. I attached patch for pgpool-II 3.3. If your pgpool's version is different and patch doesn't work, please tell me or get the latest version from the git repository. http://git.postgresql.org/gitweb/?p=pgpool2.git;a=summary |
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| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2014-02-08 06:13 | hootfrancois | New Issue | |
| 2014-02-08 06:16 | hootfrancois | Note Added: 0000391 | |
| 2014-02-08 07:12 | hootfrancois | Note Added: 0000392 | |
| 2014-02-19 07:27 | hootfrancois | Note Added: 0000393 | |
| 2014-02-26 16:41 | nagata | Assigned To | => nagata |
| 2014-02-26 16:41 | nagata | Status | new => assigned |
| 2014-02-28 18:03 | nagata | Note Added: 0000396 | |
| 2014-02-28 18:04 | nagata | File Added: parallel_segfault.patch | |
| 2015-01-08 16:13 | nagata | Status | assigned => closed |
| 2015-01-08 16:13 | nagata | Resolution | open => fixed |
