1 # phpMyAdmin Advisory rules file
2 # Use only UNIX style newlines
3 # This file is being parsed by Advisor.class.php, which should handle syntax errors correctly.
4 # However, PHP Warnings and the like are being consumed by the phpMyAdmin error handler, so those won't show up
5 # E.g.: Justification line is empty because you used an unescape percent sign, sprintf() returns an empty string and no warning/error is shown
8 # 'rule' identifier[the name of the rule] eexpr [an optional precondition]
9 # expr [variable or value calculation used for the test]
10 # expr [test, if evaluted to 'true' it fires the rule. Use 'value' to insert the calculated value (without quotes)]
11 # string [the issue (what is the problem?)]
12 # string [the recommendation (how do i fix it?)]
13 # formatted-string '|' comma-seperated-expr [the justification (result of the calculated value / why did this rule fire?)]
15 # comma-seperated-expr: expr(,expr)*
16 # eexpr: [expr] - expr enclosed in []
17 # expr: a php code literal with extras:
18 # - variable names are replaced with their respective values
19 # - fired('name of rule') is replaced with true/false when given rule has been fired. Note however that this is a very simple rules engine. Rules are only checked in sequential order as they are written down here. If given rule has not been checked yet, fired() will always evaluate to false
20 # - 'value' is replaced with the calculated value. If it is a string, it will be put within single quotes
21 # - other than that you may use any php function, initialized variable or constant
23 # identifier: A string enclosed in single quotes
24 # string: A quoteless string, may contain HTML. Variable names enclosed in curly braces are replaced with links to directly edit this variable. e.g. {tmp_table_size}
25 # formatted-string: You may use classic php sprintf() string formatting here, the arguments must be appended after a trailing pipe (|) as mentioned in above syntax
26 # percent signs (%) are automatically escaped (%%) in the following cases: When followed by a space, dot or comma and at the end of the line)
28 # Comments start with #
33 rule 'Uptime below one day'
36 Uptime is less than 1 day, performance tuning may not be accurate.
37 To have more accurate averages it is recommended to let the server run for longer than a day before running this analyzer
38 The uptime is only %s | PMA_timespanFormat(Uptime)
40 rule 'Questions below 1,000'
43 Fewer than 1,000 questions have been run against this server. The recommendations may not be accurate.
44 Let the server run for a longer time until it has executed a greater amount of queries.
45 Current amount of Questions: %s | Questions
47 rule 'Percentage of slow queries' [Questions > 0]
48 Slow_queries / Questions * 100
50 There is a lot of slow queries compared to the overall amount of Queries.
51 You might want to increase {long_query_time} or optimize the queries listed in the slow query log
52 The slow query rate should be below 5%, your value is %s%. | round(value,2)
54 rule 'Slow query rate' [Questions > 0]
55 (Slow_queries / Questions * 100) / Uptime
57 There is a high percentage of slow queries compared to the server uptime.
58 You might want to increase {long_query_time} or optimize the queries listed in the slow query log
59 You have a slow query rate of %s per hour, you should have less than 1% per hour. | PMA_bytime(value,2)
61 rule 'Long query time'
64 long_query_time is set to 10 seconds or more, thus only slow queries that take above 10 seconds are logged.
65 It is suggested to set {long_query_time} to a lower value, depending on your environment. Usually a value of 1-5 seconds is suggested.
66 long_query_time is currently set to %ds. | value
68 rule 'Slow query logging'
71 The slow query log is disabled.
72 Enable slow query logging by setting {log_slow_queries} to 'ON'. This will help troubleshooting badly performing queries.
73 log_slow_queries is set to 'OFF'
77 rule 'Release Series' [!PMA_DRIZZLE]
79 substr(value,0,1) <= 5 && substr(value,2,1) < 1
80 The MySQL server version less then 5.1.
81 You should upgrade, as MySQL 5.1 has improved performance, and MySQL 5.5 even more so.
82 Current version: %s | value
84 rule 'Minor Version' [! fired('Release Series')]
86 substr(value,0,1) <= 5 && substr(value,2,1) < 1 && substr(value,4,2) < 30
87 Version less than 5.1.30 (the first GA release of 5.1).
88 You should upgrade, as recent versions of MySQL 5.1 have improved performance and MySQL 5.5 even more so.
89 Current version: %s | value
91 rule 'Minor Version' [! fired('Release Series')]
93 substr(value,0,1) == 5 && substr(value,2,1) == 5 && substr(value,4,2) < 8
94 Version less than 5.5.8 (the first GA release of 5.5).
95 You should upgrade, to a stable version of MySQL 5.5
96 Current version: %s | value
100 preg_match('/source/i',value)
101 Version is compiled from source, not a MySQL official binary.
102 If you did not compile from source, you may be using a package modified by a distribution. The MySQL manual only is accurate for official MySQL binaries, not any package distributions (such as RedHat, Debian/Ubuntu etc).
103 'source' found in version_comment
107 preg_match('/percona/i',value)
108 The MySQL manual only is accurate for official MySQL binaries.
109 Percona documentation is at http://www.percona.com/docs/wiki/
110 'percona' found in version_comment
112 rule 'MySQL Architecture'
114 value > 3072*1024 && !preg_match('/64/',version_compile_machine) && !preg_match('/64/',version_compile_os)
115 MySQL is not compiled as a 64-bit package.
116 Your memory capacity is above 3 GiB (assuming the Server is on localhost), so MySQL might not be able to access all of your memory. You might want to consider installing the 64-bit version of MySQL.
117 Available memory on this host: %s | implode(' ',PMA_formatByteDown(value*1024, 2, 2))
122 # Lame: 'ON' == 0 is true, so you need to compare 'ON' == '0'
123 rule 'Query cache disabled'
125 value == 0 || query_cache_type == 'OFF' || query_cache_type == '0'
126 The query cache is not enabled.
127 The query cache is known to greatly improve performance if configured correctly. Enable it by setting {query_cache_size} to a 2 digit MiB value and setting {query_cache_type} to 'ON'. <b>Note:</b> If you are using memcached, ignore this recommendation.
128 query_cache_size is set to 0 or query_cache_type is set to 'OFF'
130 rule 'Query caching method' [!fired('Query cache disabled')]
133 Suboptimal caching method.
134 You are using the MySQL Query cache with a fairly high traffic database. It might be worth considering to use <a href="http://dev.mysql.com/doc/refman/5.5/en/ha-memcached.html">memcached</a> instead of the MySQL Query cache, especially if you have multiple slaves.
135 The query cache is enabled and the server receives %d queries per second. This rule fires if there is more than 100 queries per second. | round(value,1)
137 rule 'Query cache efficiency (%)' [Com_select + Qcache_hits > 0 && !fired('Query cache disabled')]
138 Qcache_hits / (Com_select + Qcache_hits) * 100
140 Query cache not running efficiently, it has a low hit rate.
141 Consider increasing {query_cache_limit}.
142 The current query cache hit rate of %s% is below 20% | round(value,1)
144 rule 'Query cache usage' [!fired('Query cache disabled')]
145 100 - Qcache_free_memory / query_cache_size * 100
147 Less than 80% of the query cache is being utilized.
148 This might be caused by {query_cache_limit} being too low. Flushing the query cache might help as well.
149 The current ratio of free query cache memory to total query cache size is %s%. It should be above 80% | round(value,1)
151 rule 'Query cache fragmentation' [!fired('Query cache disabled')]
152 Qcache_free_blocks / (Qcache_total_blocks / 2) * 100
154 The query cache is considerably fragmented.
155 Severe fragmentation is likely to (further) increase Qcache_lowmem_prunes. This might be caused by many Query cache low memory prunes due to {query_cache_size} being too small. For a immediate but short lived fix you can flush the query cache (might lock the query cache for a long time). Carefully adjusting {query_cache_min_res_unit} to a lower value might help too, e.g. you can set it to the average size of your queries in the cache using this formula: (query_cache_size - qcache_free_memory) / qcache_queries_in_cache
156 The cache is currently fragmented by %s% , with 100% fragmentation meaning that the query cache is an alternating pattern of free and used blocks. This value should be below 20%. | round(value,1)
158 rule 'Query cache low memory prunes' [Qcache_inserts > 0 && !fired('Query cache disabled')]
159 Qcache_lowmem_prunes / Qcache_inserts * 100
161 Cached queries are removed due to low query cache memory from the query cache.
162 You might want to increase {query_cache_size}, however keep in mind that the overhead of maintaining the cache is likely to increase with its size, so do this in small increments and monitor the results.
163 The ratio of removed queries to inserted queries is %s%. The lower this value is, the better (This rules firing limit: 0.1%) | round(value,1)
165 rule 'Query cache max size' [!fired('Query cache disabled')]
168 The query cache size is above 128 MiB. Big query caches may cause significant overhead that is required to maintain the cache.
169 Depending on your environment, it might be performance increasing to reduce this value.
170 Current query cache size: %s | implode(' ',PMA_formatByteDown(value, 2, 2))
172 rule 'Query cache min result size' [!fired('Query cache disabled')]
175 The max size of the result set in the query cache is the default of 1 MiB.
176 Changing {query_cache_limit} (usually by increasing) may increase efficiency. This variable determines the maximum size a query result may have to be inserted into the query cache. If there are many query results above 1 MiB that are well cacheable (many reads, little writes) then increasing {query_cache_limit} will increase efficiency. Whereas in the case of many query results being above 1 MiB that are not very well cacheable (often invalidated due to table updates) increasing {query_cache_limit} might reduce efficiency.
177 query_cache_limit is set to 1 MiB
181 rule 'Percentage of sorts that cause temporary tables' [Sort_scan + Sort_range > 0]
182 Sort_merge_passes / (Sort_scan + Sort_range) * 100
184 Too many sorts are causing temporary tables.
185 Consider increasing sort_buffer_size and/or read_rnd_buffer_size, depending on your system memory limits
186 %s% of all sorts cause temporary tables, this value should be lower than 10%. | round(value,1)
188 rule 'Rate of sorts that cause temporary tables'
189 Sort_merge_passes / Uptime
191 Too many sorts are causing temporary tables.
192 Consider increasing sort_buffer_size and/or read_rnd_buffer_size, depending on your system memory limits
193 Temporary tables average: %s, this value should be less than 1 per hour. | PMA_bytime(value,2)
198 There are lots of rows being sorted.
199 While there is nothing wrong with a high amount of row sorting, you might want to make sure that the queries which require a lot of sorting use indexed fields in the ORDER BY clause, as this will result in much faster sorting
200 Sorted rows average: %s | PMA_bytime(value,2)
203 rule 'Rate of joins without indexes'
204 (Select_range_check + Select_scan + Select_full_join) / Uptime
206 There are too many joins without indexes.
207 This means that joins are doing full table scans. Adding indexes for the fields being used in the join conditions will greatly speed up table joins
208 Table joins average: %s, this value should be less than 1 per hour | PMA_bytime(value,2)
210 rule 'Rate of reading first index entry'
211 Handler_read_first / Uptime
213 The rate of reading the first index entry is high.
214 This usually indicates frequent full index scans. Full index scans are faster than table scans but require lots of CPU cycles in big tables, if those tables that have or had high volumes of UPDATEs and DELETEs, running 'OPTIMIZE TABLE' might reduce the amount of and/or speed up full index scans. Other than that full index scans can only be reduced by rewriting queries.
215 Index scans average: %s, this value should be less than 1 per hour | PMA_bytime(value,2)
217 rule 'Rate of reading fixed position'
218 Handler_read_rnd / Uptime
220 The rate of reading data from a fixed position is high.
221 This indicates that many queries need to sort results and/or do a full table scan, including join queries that do not use indexes. Add indexes where applicable.
222 Rate of reading fixed position average: %s, this value should be less than 1 per hour | PMA_bytime(value,2)
224 rule 'Rate of reading next table row'
225 Handler_read_rnd_next / Uptime
227 The rate of reading the next table row is high.
228 This indicates that many queries are doing full table scans. Add indexes where applicable.
229 Rate of reading next table row: %s, this value should be less than 1 per hour | PMA_bytime(value,2)
232 rule 'tmp_table_size vs. max_heap_table_size'
233 tmp_table_size - max_heap_table_size
235 tmp_table_size and max_heap_table_size are not the same.
236 If you have deliberately changed one of either: The server uses the lower value of either to determine the maximum size of in-memory tables. So if you wish to increase the in-memory table limit you will have to increase the other value as well.
237 Current values are tmp_table_size: %s, max_heap_table_size: %s | implode(' ',PMA_formatByteDown(tmp_table_size, 2, 2)), implode(' ',PMA_formatByteDown(max_heap_table_size, 2, 2))
239 rule 'Percentage of temp tables on disk' [Created_tmp_tables + Created_tmp_disk_tables > 0]
240 Created_tmp_disk_tables / (Created_tmp_tables + Created_tmp_disk_tables) * 100
242 Many temporary tables are being written to disk instead of being kept in memory.
243 Increasing {max_heap_table_size} and {tmp_table_size} might help. However some temporary tables are always being written to disk, independent of the value of these variables. To eliminate these you will have to rewrite your queries to avoid those conditions (Within a temporary table: Presence of a BLOB or TEXT column or presence of a column bigger than 512 bytes) as mentioned in the beginning of an <a href="http://www.facebook.com/note.php?note_id=10150111255065841&comments">Article by the Pythian Group</a>
244 %s% of all temporary tables are being written to disk, this value should be below 25% | round(value,1)
246 rule 'Temp disk rate'
247 Created_tmp_disk_tables / Uptime
249 Many temporary tables are being written to disk instead of being kept in memory.
250 Increasing {max_heap_table_size} and {tmp_table_size} might help. However some temporary tables are always being written to disk, independent of the value of these variables. To eliminate these you will have to rewrite your queries to avoid those conditions (Within a temprorary table: Presence of a BLOB or TEXT column or presence of a column bigger than 512 bytes) as mentioned in in the <a href="http://dev.mysql.com/doc/refman/5.5/en/internal-temporary-tables.html">MySQL Documentation</a>
251 Rate of temporay tables being written to disk: %s, this value should be less than 1 per hour | PMA_bytime(value,2)
253 # I couldn't find any source on the internet that suggests a direct relation between high counts of temporary tables and any of these variables.
254 # Several independent Blog entries suggest (http://ronaldbradford.com/blog/more-on-understanding-sort_buffer_size-2010-05-10/ and http://www.xaprb.com/blog/2010/05/09/how-to-tune-mysqls-sort_buffer_size/)
255 # that sort_buffer_size should be left as it is. And increasing read_buffer_size is only suggested when there are a lot of
256 # table scans (http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html#sysvar_read_buffer_size and other sources) though
257 # setting it too high is bad too (http://www.mysqlperformanceblog.com/2007/09/17/mysql-what-read_buffer_size-value-is-optimal/).
258 #rule 'Temp table rate'
259 # Created_tmp_tables / Uptime
260 # value * 60 * 60 > 1
261 # Many intermediate temporary tables are being created.
262 # This may be caused by queries under certain conditions as mentioned in the <a href="http://dev.mysql.com/doc/refman/5.5/en/internal-temporary-tables.html">MySQL Documentation</a>. Consider increasing {sort_buffer_size} (sorting), {read_rnd_buffer_size} (random read buffer, ie, post-sort), {read_buffer_size} (sequential scan).
266 rule 'MyISAM key buffer size'
269 Key buffer is not initialized. No MyISAM indexes will be cached.
270 Set {key_buffer_size} depending on the size of your MyISAM indexes. 64M is a good start.
273 rule 'Max % MyISAM key buffer ever used' [key_buffer_size > 0]
274 Key_blocks_used * key_cache_block_size / key_buffer_size * 100
276 MyISAM key buffer (index cache) % used is low.
277 You may need to decrease the size of {key_buffer_size}, re-examine your tables to see if indexes have been removed, or examine queries and expectations about what indexes are being used.
278 max % MyISAM key buffer ever used: %s, this value should be above 95% | round(value,1)
280 # Don't fire if above rule fired - we don't need the same advice twice
281 rule 'Percentage of MyISAM key buffer used' [key_buffer_size > 0 && !fired('max % MyISAM key buffer ever used')]
282 ( 1 - Key_blocks_unused * key_cache_block_size / key_buffer_size) * 100
284 MyISAM key buffer (index cache) % used is low.
285 You may need to decrease the size of {key_buffer_size}, re-examine your tables to see if indexes have been removed, or examine queries and expectations about what indexes are being used.
286 % MyISAM key buffer used: %s, this value should be above 95% | round(value,1)
288 rule 'Percentage of index reads from memory' [Key_read_requests > 0]
289 100 - (Key_reads / Key_read_requests * 100)
291 The % of indexes that use the MyISAM key buffer is low.
292 You may need to increase {key_buffer_size}.
293 Index reads from memory: %s%, this value should be above 95% | round(value,1)
297 rule 'Rate of table open'
298 Opened_tables / Uptime
300 The rate of opening tables is high.
301 Opening tables requires disk I/O which is costly. Increasing {table_open_cache} might avoid this.
302 Opened table rate: %s, this value should be less than 10 per hour | PMA_bytime(value,2)
304 rule 'Percentage of used open files limit'
305 Open_files / open_files_limit * 100
307 The number of open files is approaching the max number of open files. You may get a "Too many open files" error.
308 Consider increasing {open_files_limit}, and check the error log when restarting after changing open_files_limit.
309 The number of opened files is at %s% of the limit. It should be below 85% | round(value,1)
311 rule 'Rate of open files'
314 The rate of opening files is high.
315 Consider increasing {open_files_limit}, and check the error log when restarting after changing open_files_limit.
316 Opened files rate: %s, this value should be less than 5 per hour | PMA_bytime(value,2)
318 rule 'Immediate table locks %' [Table_locks_waited + Table_locks_immediate > 0]
319 Table_locks_immediate / (Table_locks_waited + Table_locks_immediate) * 100
321 Too many table locks were not granted immediately.
322 Optimize queries and/or use InnoDB to reduce lock wait.
323 Immediate table locks: %s%, this value should be above 95% | round(value,1)
325 rule 'Table lock wait rate'
326 Table_locks_waited / Uptime
328 Too many table locks were not granted immediately.
329 Optimize queries and/or use InnoDB to reduce lock wait.
330 Table lock wait rate: %s, this value should be less than 1 per hour | PMA_bytime(value,2)
335 Thread cache is disabled, resulting in more overhead from new connections to MySQL.
336 Enable the thread cache by setting {thread_cache_size} > 0.
337 The thread cache is set to 0
339 rule 'Thread cache hit rate %' [thread_cache_size > 0]
340 100 - Threads_created / Connections
342 Thread cache is not efficient.
343 Increase {thread_cache_size}.
344 Thread cache hitrate: %s%, this value should be above 80% | round(value,1)
346 rule 'Threads that are slow to launch' [slow_launch_time > 0]
349 There are too many threads that are slow to launch.
350 This generally happens in case of general system overload as it is pretty simple operations. You might want to monitor your system load carefully.
351 %s thread(s) took longer than %s seconds to start, it should be 0 | value, slow_launch_time
353 rule 'Slow launch time'
356 Slow_launch_threads is above 2s
357 Set slow_launch_time to 1s or 2s to correctly count threads that are slow to launch
358 slow_launch_time is set to %s | value
362 rule 'Percentage of used connections'
363 Max_used_connections / max_connections * 100
365 The maximum amount of used connections is getting close to the value of max_connections.
366 Increase max_connections, or decrease wait_timeout so that connections that do not close database handlers properly get killed sooner. Make sure the code closes database handlers properly.
367 Max_used_connections is at %s% of max_connections, it should be below 80% | round(value,1)
369 rule 'Percentage of aborted connections'
370 Aborted_connects / Connections * 100
372 Too many connections are aborted.
373 Connections are usually aborted when they cannot be authorized. <a href="http://www.mysqlperformanceblog.com/2008/08/23/how-to-track-down-the-source-of-aborted_connects/">This article</a> might help you track down the source.
374 %s% of all connections are aborted. This value should be below 1% | round(value,1)
376 rule 'Rate of aborted connections'
377 Aborted_connects / Uptime
379 Too many connections are aborted
380 Connections are usually aborted when they cannot be authorized. <a href="http://www.mysqlperformanceblog.com/2008/08/23/how-to-track-down-the-source-of-aborted_connects/">This article</a> might help you track down the source.
381 Aborted connections rate is at %s, this value should be less than 1 per hour | PMA_bytime(value,2)
383 rule 'Percentage of aborted clients'
384 Aborted_clients / Connections * 100
386 Too many clients are aborted.
387 Clients are usually aborted when they did not close their connection to MySQL properly. This can be due to network issues or code not closing a database handler properly. Check your network and code.
388 %s% of all clients are aborted. This value should be below 2% | round(value,1)
390 rule 'Rate of aborted clients'
391 Aborted_clients / Uptime
393 Too many clients are aborted.
394 Clients are usually aborted when they did not close their connection to MySQL properly. This can be due to network issues or code not closing a database handler properly. Check your network and code.
395 Aborted client rate is at %s, this value should be less than 1 per hour | PMA_bytime(value,2)
399 rule 'Is InnoDB disabled?'
402 You do not have InnoDB enabled.
403 InnoDB is usually the better choice for table engines.
404 have_innodb is set to 'value'
406 rule 'InnoDB log size' [innodb_buffer_pool_size > 0]
407 innodb_log_file_size / innodb_buffer_pool_size * 100
409 The InnoDB log file size is not an appropriate size, in relation to the InnoDB buffer pool.
410 Especially one a system with a lot of writes to InnoDB tables you should set innodb_log_file_size to 25% of {innodb_buffer_pool_size}. However the bigger this value, the longer the recovery time will be when database crashes, so this value should not be set much higher than 256 MiB. Please note however that you cannot simply change the value of this variable. You need to shutdown the server, remove the InnoDB log files, set the new value in my.cnf, start the server, then check the error logs if everything went fine. See also <a href="http://mysqldatabaseadministration.blogspot.com/2007/01/increase-innodblogfilesize-proper-way.html">this blog entry</a>
411 Your InnoDB log size is at %s% in relation to the InnoDB buffer pool size, it should not be below 20% | round(value,1)
413 rule 'Max InnoDB log size' [innodb_buffer_pool_size > 0 && innodb_log_file_size / innodb_buffer_pool_size * 100 < 30]
414 innodb_log_file_size / (1024 * 1024)
416 The InnoDB log file size is inadequately large.
417 It is usually sufficient to set innodb_log_file_size to 25% of the size of {innodb_buffer_pool_size}. A very innodb_log_file_size slows down the recovery time after a database crash considerably. See also <a href="http://www.mysqlperformanceblog.com/2006/07/03/choosing-proper-innodb_log_file_size/">this Article</a>. You need to shutdown the server, remove the InnoDB log files, set the new value in my.cnf, start the server, then check the error logs if everything went fine. See also <a href="http://mysqldatabaseadministration.blogspot.com/2007/01/increase-innodblogfilesize-proper-way.html">this blog entry</a>
418 Your absolute InnoD log size is %s MiB | round(value,1)
420 rule 'InnoDB buffer pool size' [system_memory > 0]
421 innodb_buffer_pool_size / system_memory * 100
423 Your InnoDB buffer pool is fairly small.
424 The InnoDB buffer pool has a profound impact on performance for InnoDB tables. Assign all your remaining memory to this buffer. For database servers that use solely InnoDB as storage engine and have no other services (e.g. a web server) running, you may set this as high as 80% of your available memory. If that is not the case, you need to carefully assess the memory consumption of your other services and non-InnoDB-Tables and set this variable accordingly. If it is set too high, your system will start swapping, which decreases performance significantly. See also <a href="http://www.mysqlperformanceblog.com/2007/11/03/choosing-innodb_buffer_pool_size/">this article</a>
425 You are currently using %s% of your memory for the InnoDB buffer pool. This rule fires if you are assigning less than 60%, however this might be perfectly adequate for your system if you don't have much InnoDB tables or other services running on the same machine. | value
429 rule 'MyISAM concurrent inserts'
431 value === 0 || value === 'NEVER'
432 Enable concurrent_insert by setting it to 1
433 Setting {concurrent_insert} to 1 reduces contention between readers and writers for a given table. See also <a href="http://dev.mysql.com/doc/refman/5.5/en/concurrent-inserts.html">MySQL Documentation</a>
434 concurrent_insert is set to 0
436 # INSERT DELAYED USAGE
438 #Delayed_insert_threads 0
440 #Not_flushed_delayed_rows