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  1. MariaDB ColumnStore
  2. MCOL-3369

ExeMgr stops processing queries

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Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Unresolved
    • 1.0.0
    • None
    • ExeMgr
    • 1UM-1PM ; mcs deployed on CentOS7

    Description

      ExeMgr stops processing queries

      Issue appears sporadically after some number of queries were being processed.

      First occurrence was observed when
      query stream composed of 46 queries was sent towards DB loaded with 1TB data.
      the 45th query from the stream hung for hours .

      The seconds occurrence was observed after 2 times successful executes of the entire stream
      with the 45 queries , but after passing more 10 queues, this time one by one and getting the exec time of each – it appeared again hung of query.
      It remained in the processlist for hours in case of it's expected exec tine is 5-6 mins.

      Both times the getActiveSQLStatements returned nothing, the ExeMgr takes 100% CPU usage

      [root@um1 ~]#  /usr/local/mariadb/columnstore/bin/mcsadmin  getActiveSQLStatements
       
      WARNING: running on non Parent OAM Module, can't make configuration changes in this session.
               Access Console from 'pm1' if you need to make changes.
       
      getactivesqlstatements   Thu Jun  6 15:02:34 2019
       
      Get List of Active SQL Statements
      =================================
       
      No Active SQL Statements at this time
       
      [root@um1 ~]# /usr/local/mariadb/columnstore/mysql/bin/mysql -u root -p1
      Welcome to the MariaDB monitor.  Commands end with ; or \g.
      Your MariaDB connection id is 111
      Server version: 10.1.38-MariaDB Columnstore 1.0.17-1
       
      Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
       
      Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
       
      MariaDB [(none)]> show processlist ;
      +-----+------+-----------+---------------------+---------+-------+----------------+-----------------------------------------------------------------------------+----------+
      | Id  | User | Host      | db                  | Command | Time  | State          | Info                                                                        | Progress |
      +-----+------+-----------+---------------------+---------+-------+----------------+-----------------------------------------------------------------------------+----------+
      | 107 | root | um1:41054 | tpcds_1000          | Query   | 52745 | Sorting result | select *  from infinidb_vtable.$vtable_107 order by 1, 2, 3, 4 limit 0, 100 |    0.000 |
      | 108 | root | localhost | infinidb_querystats | Sleep   | 12128 |                | NULL                                                                        |    0.000 |
      | 111 | root | localhost | NULL                | Query   |     0 | init           | show processlist                                                            |    0.000 |
      +-----+------+-----------+---------------------+---------+-------+----------------+-----------------------------------------------------------------------------+----------+
      3 rows in set (0.00 sec)
       
      
      

      top - 15:04:47 up 1 day, 55 min,  6 users,  load average: 1.00, 1.00, 1.04
      Tasks: 219 total,   1 running, 210 sleeping,   8 stopped,   0 zombie
      %Cpu(s): 25.2 us,  0.2 sy,  0.0 ni, 74.6 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
      KiB Mem : 61848088 total, 38212916 free, 19745964 used,  3889208 buff/cache
      KiB Swap:  1048572 total,  1048572 free,        0 used. 41593956 avail Mem
       
        PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
      20561 root      19  -1   26.7g  17.8g  12060 S 100.0 30.2   1111:25 ExeMgr
       5074 root      20   0  162020   2392   1592 R   0.3  0.0   0:00.07 top
      20301 mysql     20   0 1369188 265140  20252 S   0.3  0.4   1:22.24 mysqld
          1 root      20   0  190968   3916   2580 S   0.0  0.0   0:01.44 systemd
          2 root      20   0       0      0      0 S   0.0  0.0   0:00.02 kthreadd
          3 root      20   0       0      0      0 S   0.0  0.0   0:00.83 ksoftirqd/0
          5 root       0 -20       0      0      0 S   0.0  0.0   0:00.00 kworker/0:0H
      
      

      First hanging observed at query:

      select
              s_store_name,
              i_item_desc,
              sc.revenue,
              i_current_price,
              i_wholesale_cost,
              i_brand
       from store, item,
           (select ss_store_sk, avg(revenue) as ave
              from
                  (select  ss_store_sk, ss_item_sk,
                           sum(ss_sales_price) as revenue
                      from store_sales, date_dim
                      where ss_sold_date_sk = d_date_sk and d_month_seq between 1187 and 1187+11
                      group by ss_store_sk, ss_item_sk) sa
              group by ss_store_sk) sb,
           (select  ss_store_sk, ss_item_sk, sum(ss_sales_price) as revenue
              from store_sales, date_dim
              where ss_sold_date_sk = d_date_sk and d_month_seq between 1187 and 1187+11
              group by ss_store_sk, ss_item_sk) sc
       where sb.ss_store_sk = sc.ss_store_sk and
             sc.revenue <= 0.1 * sb.ave and
             s_store_sk = sc.ss_store_sk and
             i_item_sk = sc.ss_item_sk
       order by s_store_name, i_item_desc
      limit 100;
      
      

      Second hanging observed at query:

      select
       i_item_id
       ,i_item_desc
       ,s_store_id
       ,s_store_name
       ,sum(ss_net_profit) as store_sales_profit
       ,sum(sr_net_loss) as store_returns_loss
       ,sum(cs_net_profit) as catalog_sales_profit
       from
       store_sales
       ,store_returns
       ,catalog_sales
       ,date_dim d1
       ,date_dim d2
       ,date_dim d3
       ,store
       ,item
       where
       d1.d_moy = 4
       and d1.d_year = 2001
       and d1.d_date_sk = ss_sold_date_sk
       and i_item_sk = ss_item_sk
       and s_store_sk = ss_store_sk
       and ss_customer_sk = sr_customer_sk
       and ss_item_sk = sr_item_sk
       and ss_ticket_number = sr_ticket_number
       and sr_returned_date_sk = d2.d_date_sk
       and d2.d_moy between 4 and 10
       and d2.d_year = 2001
       and sr_customer_sk = cs_bill_customer_sk
       and sr_item_sk = cs_item_sk
       and cs_sold_date_sk = d3.d_date_sk
       and d3.d_moy between 4 and  10
       and d3.d_year = 2001
       group by
       i_item_id
       ,i_item_desc
       ,s_store_id
       ,s_store_name
       order by
       i_item_id
       ,i_item_desc
       ,s_store_id
       ,s_store_name
       limit 100;
      
      

      Attachments

        1. dump_ExeMg.txt
          20 kB
          Zdravelina Sokolovska
        2. dump_PrimProc.txt
          23 kB
          Zdravelina Sokolovska
        3. um_logs.txt
          93 kB
          Zdravelina Sokolovska

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            Unassigned Unassigned
            winstone Zdravelina Sokolovska (Inactive)
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            Dates

              Created:
              Updated:

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