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  1. MariaDB Server
  2. MDEV-17845

Extreme high open file limit used

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    Details

    • Type: Bug
    • Status: Closed (View Workflow)
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 10.3, 10.3.10, 10.4
    • Fix Version/s: 10.3.15, 10.4.5
    • Component/s: Server
    • Labels:
      None
    • Environment:
      CentOs 7.4, xenforo 1.5.x

      Description

      Recently i upgraded to MariaDB 10.3.10 using directadmin custombuild function. And i noticed the mysql performance not very good. and while checking mysqltuner.pl suggestion, i found the number open file limit used extremely high.

      -------- Storage Engine Statistics -----------------------------------------------------------------
      [--] Status: +Aria +CSV +InnoDB +MEMORY +MRG_MyISAM +MyISAM +PERFORMANCE_SCHEMA +SEQUENCE
      [--] Data in MyISAM tables: 78.0M (Tables: 5)
      [--] Data in InnoDB tables: 21.1G (Tables: 236)
      [--] Data in MEMORY tables: 10.8M (Tables: 3)
      [!!] Total fragmented tables: 1

      -------- Analysis Performance Metrics --------------------------------------------------------------
      [--] innodb_stats_on_metadata: OFF
      [OK] No stat updates during querying INFORMATION_SCHEMA.

      -------- Security Recommendations ------------------------------------------------------------------
      [OK] There are no anonymous accounts for any database users
      [OK] All database users have passwords assigned
      [!!] There is no basic password file list!

      -------- CVE Security Recommendations --------------------------------------------------------------
      [--] Skipped due to --cvefile option undefined

      -------- Performance Metrics -----------------------------------------------------------------------
      [--] Up for: 14h 11m 59s (52M q [1K qps], 3M conn, TX: 1503G, RX: 15G)
      [--] Reads / Writes: 75% / 25%
      [--] Binary logging is disabled
      [--] Physical Memory : 94.2G
      [--] Max MySQL memory : 37.4G
      [--] Other process memory: 611.8M
      [--] Total buffers: 35.1G global + 2.9M per thread (620 max threads)
      [--] P_S Max memory usage: 531M
      [--] Galera GCache Max memory usage: 0B
      [OK] Maximum reached memory usage: 35.7G (37.94% of installed RAM)
      [OK] Maximum possible memory usage: 37.4G (39.68% of installed RAM)
      [OK] Overall possible memory usage with other process is compatible with memory available
      [OK] Slow queries: 0% (0/52M)
      [OK] Highest usage of available connections: 7% (45/620)
      [OK] Aborted connections: 0.00% (0/3451781)
      [--] Skipped name resolution test due to skip_networking=ON in system variables.
      [OK] Query cache is disabled by default due to mutex contention on multiprocessor machines.
      [OK] Sorts requiring temporary tables: 0% (78 temp sorts / 3M sorts)
      [!!] Joins performed without indexes: 837224
      [!!] Temporary tables created on disk: 50% (1M on disk / 3M total)
      [OK] Thread cache hit rate: 99% (45 created / 3M connections)
      [OK] Table cache hit rate: 90% (667 open / 735 opened)
      *[!!] Open file limit used: 28147927174348900% (18446744073B/65K)
      *[!!] Table locks acquired immediately: 86%

      -------- Performance schema ------------------------------------------------------------------------
      [--] Memory used by P_S: 531.1M
      [--] Sys schema isn't installed.

      -------- ThreadPool Metrics ------------------------------------------------------------------------
      [--] ThreadPool stat is enabled.
      [--] Thread Pool Size: 36 thread(s).
      [--] Using default value is good enough for your version (10.3.10-MariaDB)

      -------- MyISAM Metrics ----------------------------------------------------------------------------
      [!!] Key buffer used: 19.5% (516M used / 2B cache)
      [OK] Key buffer size / total MyISAM indexes: 2.5G/16.8M
      [OK] Read Key buffer hit rate: 100.0% (98M cached / 10K reads)
      [!!] Write Key buffer hit rate: 88.3% (7M cached / 6M writes)

      -------- InnoDB Metrics ----------------------------------------------------------------------------
      [--] InnoDB is enabled.
      [--] InnoDB Thread Concurrency: 0
      [OK] InnoDB File per table is activated
      [OK] InnoDB buffer pool / data size: 32.0G/21.1G
      [OK] Ratio InnoDB log file size / InnoDB Buffer pool size: 4.0G * 2/32.0G should be equal 25%
      [OK] InnoDB buffer pool instances: 32
      [--] Number of InnoDB Buffer Pool Chunk : 256 for 32 Buffer Pool Instance(s)
      [OK] Innodb_buffer_pool_size aligned with Innodb_buffer_pool_chunk_size & Innodb_buffer_pool_instances
      [OK] InnoDB Read buffer efficiency: 100.00% (36999275046 hits/ 37000117624 total)
      [!!] InnoDB Write Log efficiency: 86.04% (3658360 hits/ 4251694 total)
      [OK] InnoDB log waits: 0.00% (0 waits / 593334 writes)

      -------- AriaDB Metrics ----------------------------------------------------------------------------
      [--] AriaDB is enabled.
      [OK] Aria pagecache size / total Aria indexes: 128.0M/1B
      [OK] Aria pagecache hit rate: 98.5% (106M cached / 1M reads)

      -------- TokuDB Metrics ----------------------------------------------------------------------------
      [--] TokuDB is disabled.

      -------- XtraDB Metrics ----------------------------------------------------------------------------
      [--] XtraDB is disabled.

      -------- Galera Metrics ----------------------------------------------------------------------------
      [--] Galera is disabled.

      -------- Replication Metrics -----------------------------------------------------------------------
      [--] Galera Synchronous replication: NO
      [--] No replication slave(s) for this server.
      [--] Binlog format: MIXED
      [--] XA support enabled: ON
      [--] Semi synchronous replication Master: OFF
      [--] Semi synchronous replication Slave: OFF
      [--] This is a standalone server

      -------- Recommendations ---------------------------------------------------------------------------
      General recommendations:
      Run OPTIMIZE TABLE to defragment tables for better performance
      OPTIMIZE TABLE admin_xxxxx.`xf_search`; – can free 37 MB
      Total freed space after theses OPTIMIZE TABLE : 37 Mb
      MySQL was started within the last 24 hours - recommendations may be inaccurate
      Adjust your join queries to always utilize indexes
      Temporary table size is already large - reduce result set size
      Reduce your SELECT DISTINCT queries without LIMIT clauses
      Optimize queries and/or use InnoDB to reduce lock wait
      Consider installing Sys schema from https://github.com/mysql/mysql-sys
      Variables to adjust:
      join_buffer_size (> 256.0K, or always use indexes with JOINs)
      open_files_limit (> 65535)

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            Assignee:
            serg Sergei Golubchik
            Reporter:
            Nhat Minh
            Votes:
            1 Vote for this issue
            Watchers:
            8 Start watching this issue

              Dates

              Created:
              Updated:
              Resolved: