oqgraph-dev team mailing list archive

[Heinz Wiesinger <HMWiesinger@xxxxxxxxxxx>]

Hello!

I've been updating one of my applications from OQGraphv2 to v3 and while
initial tests showed everything working, I'm now getting troublesome crashes
when I put some load on the OQGraph table.

The application is basically a webservice (in PHP) that queries the OQGraph
table (schema attached) and returns the result. The query in itself should be
fairly simple:

SELECT db.* FROM db_history AS db INNER JOIN version_history AS v ON db.nodeID
= v.linkid WHERE origid = 1 AND destid = 3 AND latch = 'dijkstras';

When doing single sequential requests in the browser, everything works fine.
But once I started to put some load on the webservice (using siege as load
testing tool), MariaDB crashes quickly after 1-2 requests (crash dump
attached), always with the same crash dump.

I should note that the database setup is a master-slave replication setup. I'm
not sure that has anything to do with the crashes I'm seeing though.

I can reproduce this fairly easily and reliably in my test environment, on
both the slave and the master node, but have not been successful so far in
producing a test case that does not involve running siege.

I would really appreciate if someone could help me track this crash down.

Grs,
Heinz

Version: '10.0.11-MariaDB-log'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MariaDB Server
140527  9:24:31 [ERROR] mysqld got signal 11 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.

To report this bug, see http://kb.askmonty.org/en/reporting-bugs

We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed,
something is definitely wrong and this may fail.

Server version: 10.0.11-MariaDB-log
key_buffer_size3554432
read_buffer_size1072
max_used_connections=5
max_threadsP2
thread_count=3
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1135484 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x0x7f1d967e8008
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 0x7f1e039fdce0 thread_stack 0x48000
/usr/sbin/mysqld(my_print_stacktrace+0x2b)[0xb6893b]
/usr/sbin/mysqld(handle_fatal_signal+0x398)[0x723858]
/lib64/libpthread.so.0[0x36bc00f710]
/usr/sbin/mysqld(_ZN7handler17ha_index_read_mapEPhPKhm16ha_rkey_function+0xc9)[0x727fb9]
/usr/lib64/mysql/plugin/ha_oqgraph.so(_ZN8oqgraph36cursor7seek_toEN5boost8optionalIyEES3_+0x85d)[0x7f1d86fe882d]
/usr/lib64/mysql/plugin/ha_oqgraph.so(_ZN5boost11find_vertexEyRKN8oqgraph35graphE+0x6b)[0x7f1d86fdd83b]
/usr/lib64/mysql/plugin/ha_oqgraph.so(_ZNK10open_query13oqgraph_share11find_vertexEy+0x1a)[0x7f1d86fdabca]
/usr/lib64/mysql/plugin/ha_oqgraph.so(_ZN10open_query7oqgraph6searchEPiPyS2_+0x8c)[0x7f1d86fdbe0c]
/usr/lib64/mysql/plugin/ha_oqgraph.so(_ZN10ha_oqgraph14index_read_idxEPhjPKhj16ha_rkey_function+0x36b)[0x7f1d86fd9acb]
/usr/sbin/mysqld(_ZN7handler17ha_index_read_mapEPhPKhm16ha_rkey_function+0x83)[0x727f73]
/usr/sbin/mysqld(_ZN7handler16read_range_firstEPK12st_key_rangeS2_bb+0xbb)[0x72874b]
/usr/sbin/mysqld(_ZN7handler21multi_range_read_nextEPPv+0x89)[0x6ba9f9]
/usr/sbin/mysqld(_ZN18QUICK_RANGE_SELECT8get_nextEv+0x52)[0x7f1a62]
/usr/sbin/mysqld(_Z8filesortP3THDP5TABLEP13st_sort_fieldjP10SQL_SELECTybPyS7_+0x1190)[0x722880]
/usr/sbin/mysqld[0x60d937]
/usr/sbin/mysqld(_ZN4JOIN10exec_innerEv+0x94f)[0x61de6f]
/usr/sbin/mysqld(_ZN4JOIN4execEv+0x11)[0x61fdd1]
/usr/sbin/mysqld(_Z12mysql_selectP3THDPPP4ItemP10TABLE_LISTjR4ListIS1_ES2_jP8st_orderSB_S2_SB_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x1dd)[0x61c99d]
/usr/sbin/mysqld(_Z13handle_selectP3THDP3LEXP13select_resultm+0x28d)[0x62012d]
/usr/sbin/mysqld[0x5c7866]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x4ba7)[0x5d2477]
/usr/sbin/mysqld[0x5d4052]
/usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x1b20)[0x5d6210]
/usr/sbin/mysqld(_Z24do_handle_one_connectionP3THD+0x453)[0x6938f3]
/usr/sbin/mysqld(handle_one_connection+0x42)[0x6939c2]
/usr/sbin/mysqld[0xa5e91d]
/lib64/libpthread.so.0[0x36bc0079d1]
/lib64/libc.so.6(clone+0x6d)[0x36bb8e8b7d]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x7f1d76165020): is an invalid pointer
Connection ID (thread ID): 4790
Status: NOT_KILLED

Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on,extended_keys=on,exists_to_in=off

CREATE TABLE IF NOT EXISTS db_history (
    version varchar(10) NOT NULL,
    updateJSON mediumtext,
    prevVersion varchar(10) NOT NULL,
    nodeID bigint(20) unsigned DEFAULT NULL,
    prevNodeID bigint(20) unsigned DEFAULT NULL,
    PRIMARY KEY (prevNodeID, nodeID),
    INDEX USING BTREE (version),
    INDEX USING BTREE (prevVersion),
    KEY (nodeID)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

CREATE TABLE IF NOT EXISTS version_history (
    latch VARCHAR(32) NULL,
    origid BIGINT UNSIGNED NULL,
    destid BIGINT UNSIGNED NULL,
    weight DOUBLE NULL,
    seq BIGINT UNSIGNED NULL,
    linkid BIGINT UNSIGNED NULL,
    KEY (latch, origid, destid) USING HASH,
    KEY (latch, destid, origid) USING HASH
) ENGINE=OQGRAPH
  data_table='db_history'
  origid='prevNodeID'
  destid='nodeID';

Attachment: signature.asc
Description: This is a digitally signed message part.