MySQL 5.6 performance_schema not showing queries from application

Question

I'm seeing a strange problem with perfromance_schema... it seems queries are not getting logged as I expect them to be. For example, this is what I get:

mysql> SELECT `SCHEMA_NAME`, `DIGEST_TEXT`, `COUNT_STAR`, `FIRST_SEEN`, `LAST_SEEN`
       FROM `performance_schema`.`events_statements_summary_by_digest`
       WHERE `DIGEST_TEXT` NOT IN ('COMMIT' , 'START TRANSACTION') 
           AND `DIGEST_TEXT` NOT LIKE 'SHOW %' 
           AND `SCHEMA_NAME` LIKE 'mydbase' 
           AND `DIGEST_TEXT` NOT LIKE 'SET %' 
           ORDER BY `LAST_SEEN` DESC LIMIT 5; 
+-------------+--------------------------------------------------------------------------------------------------------------------------
| SCHEMA_NAME | DIGEST_TEXT                                                    | COUNT_STAR | FIRST_SEEN          | LAST_SEEN           |  
+-------------+--------------------------------------------------------------------------------------------------------------------------
| mydbase     | SELECT `SCHEMA_NAME` , `DIGEST_TEXT` , `COUNT_STAR` , .......  |          6 | 2016-05-04 22:56:20 | 2016-05-04 22:56:42 |
| mydbase     | SELECT `st` . * FROM `performance_schema` . `events_statement`.|         39 | 2016-05-02 10:55:30 | 2016-05-04 16:06:48 |
| mydbase     | SELECT `st` . * FROM `performance_schema` . `events_stages_hi  |         39 | 2016-05-02 10:55:30 | 2016-05-04 16:06:48 |
| mydbase     | SELECT `st` . * FROM `performance_schema` . `events_waits_his  |         39 | 2016-05-02 10:55:30 | 2016-05-04 16:06:48 |
+-------------+--------------------------------------------------------------------------------------------------------------------------
5 rows in set (0.00 sec)

If I run the query inside the database from mysql client (CLI), I can see queries appearing in there, but those from the actual application are missing?

I'm running MySQL 5.6.30 from IUS repository (CentOS 6).

Any ideas?

Answer 1

P_S in MySQL versions below 5.7.4 doesn't collect information regarding executed prepared statements: https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-4.html.

Maybe your application is using prepared statements instead of simple ad-hoc statements (parameters concatenated). Some client libraries, like PHP's PDO can avoid this (MySQL's) issue by emulating prepared statements in software, instead of sending them to MySQL for preparation (PDO option PDO::ATTR_EMULATE_PREPARES).