Uploaded image for project: 'MariaDB Server'
  1. MariaDB Server
  2. MDEV-19794

Spider crash with XA (10.4.x only)

    XMLWordPrintable

    Details

      Description

      Using Spider with sharding as in the documentation use cases, with a simple INSERT in a XA transaction realiably crashes it.

      It only affects 10.4.x, not reproducible with 10.3.x.

      2019-06-18  9:19:11 0 [Note] mysqld: ready for connections.
      Version: '10.4.5-MariaDB-1:10.4.5+maria~bionic'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  mariadb.org binary distribution
      190618  9:19:57 [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 https://mariadb.com/kb/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: 10.4.5-MariaDB-1:10.4.5+maria~bionic
      key_buffer_size=134217728
      read_buffer_size=2097152
      max_used_connections=1
      max_threads=102
      thread_count=27
      It is possible that mysqld could use up to 
      key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 760240 K  bytes of memory
      Hope that's ok; if not, decrease some variables in the equation.
       
      Thread pointer: 0x7f5800000c08
      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 = 0x7f58cc11add8 thread_stack 0x49000
      mysqld(my_print_stacktrace+0x2e)[0x5627474462ce]
      mysqld(handle_fatal_signal+0x515)[0x562746ec1275]
      /lib/x86_64-linux-gnu/libpthread.so.0(+0x12890)[0x7f58d3611890]
      mysqld(_Z16xid_cache_deleteP3THDP9XID_STATE+0x16)[0x562746e48e26]
      /usr/lib/mysql/plugin/ha_spider.so(_Z25spider_internal_xa_commitP3THDP21st_spider_transactionP5xid_tP5TABLES6_+0x537)[0x7f58cd2ae637]
      /usr/lib/mysql/plugin/ha_spider.so(_Z13spider_commitP10handlertonP3THDb+0xa4)[0x7f58cd2b1554]
      mysqld(+0x851ef5)[0x562746ec1ef5]
      mysqld(_Z15trans_xa_commitP3THD+0x34d)[0x562746e495cd]
      mysqld(_Z21mysql_execute_commandP3THD+0x3980)[0x562746cb6510]
      mysqld(_Z11mysql_parseP3THDPcjP12Parser_statebb+0x22a)[0x562746cbbcca]
      mysqld(_Z16dispatch_command19enum_server_commandP3THDPcjbb+0x166d)[0x562746cbe48d]
      mysqld(_Z10do_commandP3THD+0x148)[0x562746cbf8f8]
      mysqld(_Z24do_handle_one_connectionP7CONNECT+0x2c2)[0x562746d994c2]
      mysqld(handle_one_connection+0x3d)[0x562746d9958d]
      /lib/x86_64-linux-gnu/libpthread.so.0(+0x76db)[0x7f58d36066db]
      /lib/x86_64-linux-gnu/libc.so.6(clone+0x3f)[0x7f58d2a0488f]
       
      Trying to get some variables.
      Some pointers may be invalid and cause the dump to abort.
      Query (0x7f5800011f80): XA COMMIT '_sa_70fbd0dd1c31f43bb9a16f18b670eaa6'
      Connection ID (thread ID): 29
      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=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on
       
      The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
      information that should help you find out what is causing the crash.
      Writing a core file...
      Working directory at /var/lib/mysql
      Resource Limits:
      Limit                     Soft Limit           Hard Limit           Units     
      Max cpu time              unlimited            unlimited            seconds   
      Max file size             unlimited            unlimited            bytes     
      Max data size             unlimited            unlimited            bytes     
      Max stack size            8388608              unlimited            bytes     
      Max core file size        unlimited            unlimited            bytes     
      Max resident set          unlimited            unlimited            bytes     
      Max processes             unlimited            unlimited            processes 
      Max open files            1048576              1048576              files     
      Max locked memory         16777216             16777216             bytes     
      Max address space         unlimited            unlimited            bytes     
      Max file locks            unlimited            unlimited            locks     
      Max pending signals       62717                62717                signals   
      Max msgqueue size         819200               819200               bytes     
      Max nice priority         0                    0                    
      Max realtime priority     0                    0                    
      Max realtime timeout      unlimited            unlimited            us        
      Core pattern: |/usr/share/apport/apport %p %s %c %d %P
      

      Please note that spider_internal_xa is set to OFF (default), but the above traceback shows internal_xa function names.

      Backend schema:

      CREATE TABLE `mytable_shard0` (
        id INT unsigned NOT NULL,
        some_field TEXT(100) DEFAULT NULL, 
        PRIMARY KEY (`id`),
      ) ENGINE=InnoDB ROW_FORMAT=COMPACT
      

      Spider schema:

      CREATE OR REPLACE SERVER srvA
      FOREIGN DATA WRAPPER mysql 
      OPTIONS (USER 'spider', PASSWORD 'spider', PORT 3306, HOST '192.168.199.10', DATABASE 'testdb');
       
      CREATE OR REPLACE SERVER srvB
      FOREIGN DATA WRAPPER mysql 
      OPTIONS (USER 'spider', PASSWORD 'spider', PORT 3306, HOST '192.168.199.11', DATABASE 'testdb');
       
      create table mytable (
        id INT unsigned NOT NULL,
        some_field TEXT(100) DEFAULT NULL, 
        PRIMARY KEY (id),
      )
      ENGINE=spider
      partition by list (mod(id, 2)) (
          partition p00 values in(0)  comment = 'server "srvA", table "mytable_shard0"',
          partition p01 values in(1)  comment = 'server "srvB", table "mytable_shard1"'
      );
      

      Query against Spider:

      XA START 'test';
      INSERT INTO mytable (id, some_field) VALUES (0, "foo"), (1, "bar");
      XA END 'test';
      XA PREPARE 'test';
      XA COMMIT 'test';
      

      Upon the last statement (XA COMMIT 'test';), Spider crashes. I'm performing XA and not a regular transaction against Spider because of MDEV-19754.

      Observations on the network:

      • XA transaction gets handled all well with the backend servers and report their final commit just fine.
      • Spider reports to the client sometimes, but not always. Seems like a race between network socket being killed with the process. Mostly seeing Lost connection to MySQL server during query with the last statement.

        Attachments

          Activity

            People

            Assignee:
            Kentoku Kentoku Shiba
            Reporter:
            gertvdijk Gert van Dijk
            Votes:
            1 Vote for this issue
            Watchers:
            4 Start watching this issue

              Dates

              Created:
              Updated:
              Resolved: