We are having serious issues with one of our productions servers. The setup in question is CentOS 7 64-bit server with 16 GB of ram and 250GB SSD (so the setup should be very fast). The LEMP stack is configured with MariaDB 10.1.29. We are having about 20 applications running on this server, each using its own database.
Couple of weeks ago we saw in our status monitor (pinging each application in 5 minute intervals and measuring response time) that 3 applications are performing very slowly from time to time. (Response times from 2s-10s while the average is around ~0.1s). The slow log of MariaDB is full of slow queries (most of them easy insert, select and update queries for session storage) which sometimes take up to 15 seconds, but only from these three applications.
What these three applications have in common compared to the rest, they are all using InnoDB instead of MyISAM. So for further debugging we converted 3 more applications from MyISAM to InnoDB and these also started to suffer from the same delays.
I was able to catch the profile of a slow query and the problem seems to be related to query end.
The problem is (or what makes it hard to debug), we can't see any regularity and queries are working fast in 99% of the cases.
Here is a typical query from slowlog:
# Time: 171127 11:59:37
# User@Host: ci[ci] @ localhost []
# Thread_id: 10299 Schema: ci QC_hit: No
# Query_time: 6.945446 Lock_time: 0.000083 Rows_sent: 0 Rows_examined: 1
# Rows_affected: 1
#
# explain: id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
# explain: 1 SIMPLE fx_un_sessions range PRIMARY PRIMARY 386 NULL 1 1.00 100.00 100.00 Using where
#
SET timestamp=1511780377;
UPDATE `fx_un_sessions` SET `timestamp` = 1511780370, `data` = '__ci_last_regenerate|i:1511780354;requested_page|s:30:\"http://ci.test.dev/leads\";user_id|s:1:\"1\";username|s:9:\"admin\";role_id|s:1:\"1\";status|s:1:\"1\";previous_page|s:30:\"http://ci.test.dev/leads\";'
I was able to catch the output of SHOW ENGINE INNODB STATUS right after this query...so maybe you can identify the issue:
=====================================
2017-11-27 11:59:37 7fccc41adb00 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 3 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 1879 srv_active, 0 srv_shutdown, 69129 srv_idle
srv_master_thread log flush and writes: 71007
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 3583
--Thread 140517442575104 has waited at trx0sys.ic line 103 for 7.0000 seconds the semaphore:
X-lock (wait_ex) on RW-latch at 0x7fcca5efd518 '&block->lock'
a writer (thread id 140517442575104) has reserved it in mode wait exclusive
number of readers 1, waiters flag 0, lock_word: ffffffffffffffff
Last time read locked in file buf0flu.cc line 1113
Last time write locked in file trx0sys.ic line 103
Holder thread 0 file not yet reserved line 0
--Thread 140515701942016 has waited at trx0undo.ic line 191 for 7.0000 seconds the semaphore:
S-lock on RW-latch at 0x7fcca58bfa90 '&block->lock'
a writer (thread id 140517442575104) has reserved it in mode exclusive
number of readers 0, waiters flag 1, lock_word: 0
Last time read locked in file buf0flu.cc line 1113
Last time write locked in file trx0undo.ic line 171
Holder thread 0 file not yet reserved line 0
OS WAIT ARRAY INFO: signal count 3430
Mutex spin waits 5659, rounds 109128, OS waits 1956
RW-shared spins 1487, rounds 44302, OS waits 1466
RW-excl spins 29, rounds 2856, OS waits 87
Spin rounds per wait: 19.28 mutex, 29.79 RW-shared, 98.48 RW-excl
------------
TRANSACTIONS
------------
Trx id counter 13579354
Purge done for trx's n:o < 13579353 undo n:o < 0 state: running
History list length 19
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 10302, OS thread handle 0x7fccc41adb00, query id 390566 localhost pm init
SHOW ENGINE INNODB STATUS
---TRANSACTION 13253635, not started
MySQL thread id 1, OS thread handle 0x7fcccc0efb00, query id 0 Waiting for requests
---TRANSACTION 13579352, ACTIVE 7 sec committing
mysql tables in use 1, locked 1
2 lock struct(s), heap size 360, 1 row lock(s), undo log entries 1
MySQL thread id 10299, OS thread handle 0x7fccc43fdb00, query id 390535 localhost pm query end
UPDATE `fx_un_sessions` SET `timestamp` = 1511780370, `data` = '__ci_last_regenerate|i:1511780354;requested_page|s:30:\"http://ci.test.dev/leads\";user_id|s:1:\"1\";username|s:9:\"admin\";role_id|s:1:\"1\";status|s:1:\"1\";previous_page|s:30:\"http://ci.test.dev/leads\";'
WHERE `id` = '1sg79p2m7ure6ejk987eu5o5gpjir6p9'
Trx #rec lock waits 0 #table lock waits 0
Trx total rec lock wait time 0 SEC
Trx total table lock wait time 0 SEC
--------
FILE I/O
--------
I/O thread 0 state: waiting for completed aio requests (insert buffer thread)
I/O thread 1 state: waiting for completed aio requests (log thread)
I/O thread 2 state: waiting for completed aio requests (read thread)
I/O thread 3 state: waiting for completed aio requests (read thread)
I/O thread 4 state: waiting for completed aio requests (read thread)
I/O thread 5 state: waiting for completed aio requests (read thread)
I/O thread 6 state: waiting for completed aio requests (read thread)
I/O thread 7 state: waiting for completed aio requests (read thread)
I/O thread 8 state: waiting for completed aio requests (read thread)
I/O thread 9 state: waiting for completed aio requests (read thread)
I/O thread 10 state: waiting for completed aio requests (read thread)
I/O thread 11 state: waiting for completed aio requests (read thread)
I/O thread 12 state: waiting for completed aio requests (read thread)
I/O thread 13 state: waiting for completed aio requests (read thread)
I/O thread 14 state: waiting for completed aio requests (read thread)
I/O thread 15 state: waiting for completed aio requests (read thread)
I/O thread 16 state: waiting for completed aio requests (read thread)
I/O thread 17 state: waiting for completed aio requests (read thread)
I/O thread 18 state: waiting for completed aio requests (read thread)
I/O thread 19 state: waiting for completed aio requests (read thread)
I/O thread 20 state: waiting for completed aio requests (read thread)
I/O thread 21 state: waiting for completed aio requests (read thread)
I/O thread 22 state: waiting for completed aio requests (read thread)
I/O thread 23 state: waiting for completed aio requests (read thread)
I/O thread 24 state: waiting for completed aio requests (read thread)
I/O thread 25 state: waiting for completed aio requests (read thread)
I/O thread 26 state: waiting for completed aio requests (read thread)
I/O thread 27 state: waiting for completed aio requests (read thread)
I/O thread 28 state: waiting for completed aio requests (read thread)
I/O thread 29 state: waiting for completed aio requests (read thread)
I/O thread 30 state: waiting for completed aio requests (read thread)
I/O thread 31 state: waiting for completed aio requests (read thread)
I/O thread 32 state: waiting for completed aio requests (read thread)
I/O thread 33 state: waiting for completed aio requests (read thread)
I/O thread 34 state: waiting for completed aio requests (read thread)
I/O thread 35 state: waiting for completed aio requests (read thread)
I/O thread 36 state: waiting for completed aio requests (read thread)
I/O thread 37 state: waiting for completed aio requests (read thread)
I/O thread 38 state: waiting for completed aio requests (read thread)
I/O thread 39 state: waiting for completed aio requests (read thread)
I/O thread 40 state: waiting for completed aio requests (read thread)
I/O thread 41 state: waiting for completed aio requests (read thread)
I/O thread 42 state: waiting for completed aio requests (read thread)
I/O thread 43 state: waiting for completed aio requests (read thread)
I/O thread 44 state: waiting for completed aio requests (read thread)
I/O thread 45 state: waiting for completed aio requests (read thread)
I/O thread 46 state: waiting for completed aio requests (read thread)
I/O thread 47 state: waiting for completed aio requests (read thread)
I/O thread 48 state: waiting for completed aio requests (read thread)
I/O thread 49 state: waiting for completed aio requests (read thread)
I/O thread 50 state: waiting for completed aio requests (read thread)
I/O thread 51 state: waiting for completed aio requests (read thread)
I/O thread 52 state: waiting for completed aio requests (read thread)
I/O thread 53 state: waiting for completed aio requests (read thread)
I/O thread 54 state: waiting for completed aio requests (read thread)
I/O thread 55 state: waiting for completed aio requests (read thread)
I/O thread 56 state: waiting for completed aio requests (read thread)
I/O thread 57 state: waiting for completed aio requests (read thread)
I/O thread 58 state: waiting for completed aio requests (read thread)
I/O thread 59 state: waiting for completed aio requests (read thread)
I/O thread 60 state: waiting for completed aio requests (read thread)
I/O thread 61 state: waiting for completed aio requests (read thread)
I/O thread 62 state: waiting for completed aio requests (read thread)
I/O thread 63 state: waiting for completed aio requests (read thread)
I/O thread 64 state: waiting for completed aio requests (read thread)
I/O thread 65 state: waiting for completed aio requests (read thread)
I/O thread 66 state: waiting for completed aio requests (write thread)
I/O thread 67 state: waiting for completed aio requests (write thread)
I/O thread 68 state: waiting for completed aio requests (write thread)
I/O thread 69 state: waiting for completed aio requests (write thread)
I/O thread 70 state: waiting for completed aio requests (write thread)
I/O thread 71 state: waiting for completed aio requests (write thread)
I/O thread 72 state: waiting for completed aio requests (write thread)
I/O thread 73 state: waiting for completed aio requests (write thread)
I/O thread 74 state: waiting for completed aio requests (write thread)
I/O thread 75 state: waiting for completed aio requests (write thread)
I/O thread 76 state: waiting for completed aio requests (write thread)
I/O thread 77 state: waiting for completed aio requests (write thread)
I/O thread 78 state: waiting for completed aio requests (write thread)
I/O thread 79 state: waiting for completed aio requests (write thread)
I/O thread 80 state: waiting for completed aio requests (write thread)
I/O thread 81 state: waiting for completed aio requests (write thread)
I/O thread 82 state: waiting for completed aio requests (write thread)
I/O thread 83 state: waiting for completed aio requests (write thread)
I/O thread 84 state: waiting for completed aio requests (write thread)
I/O thread 85 state: waiting for completed aio requests (write thread)
I/O thread 86 state: waiting for completed aio requests (write thread)
I/O thread 87 state: waiting for completed aio requests (write thread)
I/O thread 88 state: waiting for completed aio requests (write thread)
I/O thread 89 state: waiting for completed aio requests (write thread)
I/O thread 90 state: waiting for completed aio requests (write thread)
I/O thread 91 state: waiting for completed aio requests (write thread)
I/O thread 92 state: waiting for completed aio requests (write thread)
I/O thread 93 state: waiting for completed aio requests (write thread)
I/O thread 94 state: waiting for completed aio requests (write thread)
I/O thread 95 state: waiting for completed aio requests (write thread)
I/O thread 96 state: waiting for completed aio requests (write thread)
I/O thread 97 state: waiting for completed aio requests (write thread)
I/O thread 98 state: waiting for completed aio requests (write thread)
I/O thread 99 state: waiting for completed aio requests (write thread)
I/O thread 100 state: waiting for completed aio requests (write thread)
I/O thread 101 state: waiting for completed aio requests (write thread)
I/O thread 102 state: waiting for completed aio requests (write thread)
I/O thread 103 state: waiting for completed aio requests (write thread)
I/O thread 104 state: waiting for completed aio requests (write thread)
I/O thread 105 state: waiting for completed aio requests (write thread)
I/O thread 106 state: waiting for completed aio requests (write thread)
I/O thread 107 state: waiting for completed aio requests (write thread)
I/O thread 108 state: waiting for completed aio requests (write thread)
I/O thread 109 state: waiting for completed aio requests (write thread)
I/O thread 110 state: waiting for completed aio requests (write thread)
I/O thread 111 state: waiting for completed aio requests (write thread)
I/O thread 112 state: waiting for completed aio requests (write thread)
I/O thread 113 state: waiting for completed aio requests (write thread)
I/O thread 114 state: waiting for completed aio requests (write thread)
I/O thread 115 state: waiting for completed aio requests (write thread)
I/O thread 116 state: waiting for completed aio requests (write thread)
I/O thread 117 state: waiting for completed aio requests (write thread)
I/O thread 118 state: waiting for completed aio requests (write thread)
I/O thread 119 state: waiting for completed aio requests (write thread)
I/O thread 120 state: waiting for completed aio requests (write thread)
I/O thread 121 state: waiting for completed aio requests (write thread)
I/O thread 122 state: waiting for completed aio requests (write thread)
I/O thread 123 state: waiting for completed aio requests (write thread)
I/O thread 124 state: waiting for completed aio requests (write thread)
I/O thread 125 state: waiting for completed aio requests (write thread)
I/O thread 126 state: waiting for completed aio requests (write thread)
I/O thread 127 state: waiting for completed aio requests (write thread)
I/O thread 128 state: waiting for completed aio requests (write thread)
I/O thread 129 state: waiting for completed aio requests (write thread)
Pending normal aio reads: 0 [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] ,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 1; buffer pool: 0
9448 OS file reads, 19554 OS file writes, 8683 OS fsyncs
0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2, 17 merges
merged operations:
insert 18, delete mark 0, delete 0
discarded operations:
insert 0, delete mark 0, delete 0
0.00 hash searches/s, 0.00 non-hash searches/s
---
LOG
---
Log sequence number 640945853
Log flushed up to 640942303
Pages flushed up to 640940676
Last checkpoint at 640931678
Max checkpoint age 38358836
Checkpoint age target 37160123
Modified age 5177
Checkpoint age 14175
1 pending log writes, 0 pending chkp writes
3485 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 203177984; in additional pool allocated 0
Total memory allocated by read views 288
Internal hash tables (constant factor + variable factor)
Adaptive hash index 4124640 (3071864 + 1052776)
Page hash 192776 (buffer pool 0 only)
Dictionary cache 14775380 (769456 + 14005924)
File system 1921264 (812272 + 1108992)
Lock system 481792 (480712 + 1080)
Recovery system 0 (0 + 0)
Dictionary memory allocated 14005924
Buffer pool size 11839
Buffer pool size, bytes 193970176
Free buffers 3412
Database pages 8363
Old database pages 3106
Modified db pages 17
Percent of dirty pages(LRU & free pages): 0.144
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0, flush list 2, single page 0
Pages made young 6, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 8223, created 140, written 14482
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
No buffer pool page gets since the last printout
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 8363, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
1 RW transactions active inside InnoDB
0 RO transactions active inside InnoDB
1 out of 1000 descriptors used
Main thread process no. 23228, id 140515735500544, state: flushing log
Number of rows inserted 1918, updated 912, deleted 2072, read 5537548
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 2
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
Profiling of slow query
MariaDB [user]> UPDATE `fx_un_sessions` SET `timestamp` = 1511872955 WHERE `id` = 'hrpsbbvr785cndmmo9n1iqnrek7teqi3';
Query OK, 0 rows affected (8.07 sec)
Rows matched: 1 Changed: 0 Warnings: 0
+----------------------+----------+
| Status | Duration |
+----------------------+----------+
| starting | 0.000097 |
| checking permissions | 0.000015 |
| Opening tables | 0.000031 |
| After opening tables | 0.000013 |
| System lock | 0.000012 |
| Table lock | 0.000012 |
| init | 0.000065 |
| updating | 0.000088 |
| end | 0.000016 |
| query end | 8.077103 |
| closing tables | 0.000059 |
| Unlocking tables | 0.000034 |
| freeing items | 0.000019 |
| updating status | 0.000032 |
| logging slow query | 0.000136 |
| cleaning up | 0.000035 |
+----------------------+----------+
16 rows in set (0.00 sec)
My server.cnf
[mysqld]
pid-file = /var/run/mysqld/mysqld.pid
character-set-server = utf8
collation-server = utf8_unicode_ci
skip_name_resolve = 1
thread_cache_size = 4
performance_schema
query_cache_type = 0
query_cache_limit = 0
query_cache_size = 0
join_buffer_size = 1M
tmp_table_size = 270M
max_heap_table_size = 270M
innodb_buffer_pool_instances = 1
innodb_buffer_pool_size = 200M
innodb_io_capacity = 2000
innodb_read_io_threads = 64
innodb_thread_concurrency = 0
innodb_write_io_threads = 64
innodb_log_file_size = 23M
slow_query_log = 1
slow_query_log_file = /var/log/mariadb/slow.log
log_error = /var/log/mariadb/error.log
log_slow_verbosity = query_plan,explain
long_query_time = 1
Do you have any ideas what the problem might be or how I can further debug the issue? I am kind of lost.
Update
This server is not dedicated to run MySQL only. LEMP Stack including Nginx and PHP-FPM are running as well. innodb_buffer_pool_size = 185M was calculated by using this formula:
SELECT CONCAT(CEILING(RIBPS/POWER(1024,pw)),SUBSTR(' KMGT',pw+1,1))
Recommended_InnoDB_Buffer_Pool_Size FROM
(
SELECT RIBPS,FLOOR(LOG(RIBPS)/LOG(1024)) pw
FROM
(
SELECT SUM(data_length+index_length)*1.1*growth RIBPS
FROM information_schema.tables AAA,
(SELECT 1.25 growth) BBB
WHERE ENGINE='InnoDB'
) AA
) A;
Some more requested server.cnf entries:
key_buffer_size = 134217728
Output of $ cat /proc/meminfo
MemTotal: 16267832 kB
MemFree: 2643524 kB
MemAvailable: 15089280 kB
MySQLTuner Report:
[OK] Operating on 64-bit architecture
-------- Log file Recommendations ------------------------------------------------------------------
[--] Log file: /var/log/mariadb/error.log(65K)
[OK] Log file /var/log/mariadb/error.log exists
[OK] Log file /var/log/mariadb/error.log is readable.
[OK] Log file /var/log/mariadb/error.log is not empty
[OK] Log file /var/log/mariadb/error.log is smaller than 32 Mb
[!!] /var/log/mariadb/error.log contains 34 warning(s).
[OK] /var/log/mariadb/error.log doesn't contain any error.
[--] 28 start(s) detected in /var/log/mariadb/error.log
[--] 27 shutdown(s) detected in /var/log/mariadb/error.log
-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +Aria +CSV +InnoDB +MEMORY +MRG_MyISAM +MyISAM +PERFORMANCE_SCHEMA +SEQUENCE
[--] Data in MyISAM tables: 589K (Tables: 16)
[--] Data in InnoDB tables: 135M (Tables: 1089)
[OK] Total fragmented tables: 0
-------- Security Recommendations ------------------------------------------------------------------
[OK] There are no anonymous accounts for any database users
[OK] All database users have passwords assigned
[--] There are 612 basic passwords in the list.
-------- CVE Security Recommendations --------------------------------------------------------------
[OK] NO SECURITY CVE FOUND FOR YOUR VERSION
-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 1d 7h 16m 27s (740K q [6.577 qps], 14K conn, TX: 1G, RX: 299M)
[--] Reads / Writes: 99% / 1%
[--] Binary logging is disabled
[--] Physical Memory : 15.5G
[--] Max MySQL memory : 1.4G
[--] Other process memory: 1.7G
[--] Total buffers: 750.0M global + 3.7M per thread (151 max threads)
[--] P_S Max memory usage: 92M
[--] Galera GCache Max memory usage: 0B
[OK] Maximum reached memory usage: 872.0M (5.49% of installed RAM)
[OK] Maximum possible memory usage: 1.4G (8.78% of installed RAM)
[OK] Overall possible memory usage with other process is compatible with memory available
[OK] Slow queries: 0% (327/740K)
[OK] Highest usage of available connections: 5% (8/151)
[OK] Aborted connections: 0.01% (1/14623)
[OK] Query cache is disabled by default due to mutex contention on multiprocessor machines.
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 105K sorts)
[!!] Joins performed without indexes: 24184
[!!] Temporary tables created on disk: 86% (81K on disk / 94K total)
[OK] Thread cache hit rate: 99% (48 created / 14K connections)
[OK] Table cache hit rate: 48% (2K open / 4K opened)
[OK] Open file limit used: 0% (136/16K)
[OK] Table locks acquired immediately: 100% (912K immediate / 912K locks)
-------- Performance schema ------------------------------------------------------------------------
[--] Memory used by P_S: 92.7M
[--] Sys schema isn't installed.
-------- ThreadPool Metrics ------------------------------------------------------------------------
[--] ThreadPool stat is enabled.
[--] Thread Pool Size: 4 thread(s).
[--] Using default value is good enough for your version (10.1.29-MariaDB)
-------- MyISAM Metrics ----------------------------------------------------------------------------
[!!] Key buffer used: 18.3% (24M used / 134M cache)
[OK] Key buffer size / total MyISAM indexes: 128.0M/233.0K
[!!] Read Key buffer hit rate: 72.4% (156 cached / 43 reads)
[OK] Write Key buffer hit rate: 100.0% (3 cached / 3 writes)
-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[OK] InnoDB File per table is activated
[OK] InnoDB buffer pool / data size: 200.0M/135.2M
[OK] Ratio InnoDB log file size / InnoDB Buffer pool size: 23.0M * 2/200.0M should be equal 25%
[OK] InnoDB buffer pool instances: 1
[--] InnoDB Buffer Pool Chunk Size not used or defined in your version
[OK] InnoDB Read buffer efficiency: 99.99% (118166741 hits/ 118175041 total)
[!!] InnoDB Write Log efficiency: 85.77% (37789 hits/ 44061 total)
[OK] InnoDB log waits: 0.00% (0 waits / 6272 writes)
-------- AriaDB Metrics ----------------------------------------------------------------------------
[--] AriaDB is enabled.
[OK] Aria pagecache size / total Aria indexes: 128.0M/1B
[!!] Aria pagecache hit rate: 70.9% (202K cached / 58K reads)
-------- TokuDB Metrics ----------------------------------------------------------------------------
[--] TokuDB is disabled.
-------- XtraDB Metrics ----------------------------------------------------------------------------
[--] XtraDB is disabled.
-------- RocksDB Metrics ---------------------------------------------------------------------------
[--] RocksDB is disabled.
-------- Spider Metrics ----------------------------------------------------------------------------
[--] Spider is disabled.
-------- Connect Metrics ---------------------------------------------------------------------------
[--] Connect is disabled.
-------- Galera Metrics ----------------------------------------------------------------------------
[--] Galera is disabled.
-------- Replication Metrics -----------------------------------------------------------------------
[--] Galera Synchronous replication: NO
[--] No replication slave(s) for this server.
[--] This is a standalone server.
-------- Recommendations ---------------------------------------------------------------------------
General recommendations:
Control warning line(s) into /var/log/mariadb/error.log file
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
Consider installing Sys schema from https://github.com/mysql/mysql-sys
Variables to adjust:
join_buffer_size (> 1.0M, or always use indexes with joins)