0
votes
5answers
150 views

How to determine why a MySQL server has become slow and requests sometimes time out?

I'm working on my first project that makes heavy use of a MySQL database and am struggling to understand performance issues I'm having. Most of the time, responses are returned quickly from the ...
1
vote
1answer
110 views

MySQL with high CPU and memory usage

here we have a VPS with 3.2GHz quadcore processor with 2GB of RAM and 4GB of SWAP which need to work with a high intensive legacy system (read: bad coded). The main problem is that the CPU (~80 - ...
0
votes
3answers
111 views

Large database - too much time spent opening and closing tables

I have a MySQL server (5.5.31) with 450 databases of some 200 tables each. (Yes, 90,000 tables) When we're under high load, there's over 100 concurrent queries, of which 70% are either opening or ...
3
votes
2answers
4k views

MySQL creates temporary tables on disk. How do I stop it?

We are running a site (Moodle) that the users currently find slow. I think I have tracked down the problem to MySQL creating temporary tables on disk. I watch the variable created_tmp_disk_tables in ...
0
votes
0answers
23 views

What can cause database slowness for finite time frames other than more requests or heavier requests

I'm trying to understand possible reasons for high variance in time spent in MySQL Database in my web application. There are hours in which everything is smooth, and hours that are much slower. For ...
0
votes
2answers
885 views

How to optimize MySQL for large BLOB updates

I have a table that holds large BLOBs (up to 10M), and is updated frequently. The problem is that UPDATE statements can take up to 1 second to execute, and due to app design this blocks UI. I need to ...
0
votes
1answer
68 views

Indexes and Optimizations for Logging System

I'm designing tables for a new log system and am having trouble figuring out what indexes I'll need (I'm a developer, not a DBA), and am also open to any suggestions/criticisms/etc. for making the ...
3
votes
2answers
4k views

Is my.cnf for mysql 5.5 is suitable and well tuned for below hardware spec?

My Hardware Spec Technology: Ivy Bridge CPU: Intel Xeon E3 1245v2 Intel Smart Cache: 8MB Cores / Threads: 4 / 8 Frequency: 3.4GHz+ / 3.8GHz Turbo Boost RAM: 32 GB DDR3 Hard disk: 2x 2TB SATA3 Raid 1 ...
2
votes
1answer
406 views

What causes InnoDB to write 100% more pages while slowing down answering queries?

I have a somewhat big database server: 4 processors, 32 cores, 288GB RAM, 2 ethernet cards bounded together, 2 independent RAID controller cards with 1GB cache each, 24 2.5" disks, being 8 SAS, ...
2
votes
1answer
98 views

Slow Query Gets Even Slower After Indexing

I have a MySQL database with just one table containing 8 million records. I need to query the table to find a single record that matches a specific number: select * from my_table where ...
3
votes
1answer
183 views

Find least recently used mysql table index

I am cleaning up duplicate indices from (innodb)tables in a mysql database. The database has about 50 tables. While I can check for duplicate keys using pt-duplicate-key-checker, I was wondering if ...
4
votes
2answers
838 views

Could running ANALYZE on all databases on large InnoDB tables show some performance increase?

So we have an old database that was fragmented until we ran OPTIMIZE on all tables. The database/tables are about 100GB in size. Tables are InnoDB with heavy read/write activity. There are so many ...
3
votes
1answer
408 views

NuoDB with Amazon S3

I think about developing my new mobile and web app against NuoDB. I believe in their technology. The thing that I care the most is backup and restore in case of data corruption and read / write speed ...
4
votes
1answer
2k views

Can I safely kill OPTIMIZE TABLE on an InnoDB table?

MySQL's documentation for kill warns: Warning Killing a REPAIR TABLE or OPTIMIZE TABLE operation on a MyISAM table results in a table that is corrupted and unusable. Any reads or writes to ...
1
vote
2answers
805 views

Restore data from remote server using “.sql” file

I have a ".SQL" file which contains data at a remote server. I could download that file to my local machine and import data in my local DB, but because of network issues, and the size of ".sql" file ...
1
vote
1answer
246 views

MySQL suddenly running very very slowly

I run a PHP/MySQL website on a fairly large server with 16GB RAM and 3 vCPUs. Everything was flying along until this morning when I noticed MySQL down. I tried to restart MySQL and first got the ...
2
votes
1answer
260 views

what does SHOW /*!50000 GLOBAL */ STATUS do ?

What is the difference between SHOW /*!50000 GLOBAL */ STATUS and SHOW GLOBAL STATUS I saw that in few scripts and tuning presentations the first command is being used. Is there a difference, ...
3
votes
1answer
111 views

What are some key configuration settings for using an InnoDb table for session storage?

I want to start clustering my PHP app servers but don't want to go for a sticky-sessions load balancing setup at this point. However, I want sessions that are persisted to disk and implement proper ...
3
votes
2answers
700 views

Website is too slow when number of records increases?

I have developed a web application called Referral Program, It it developed by using PHP, MySQL. Users can joining the website and when they introduce new members, he/she gets a commission. The system ...
5
votes
1answer
475 views

Should I use a storage engine other than MyISAM to optimise these tables or should I get better disks?

There's a production database I'm working on, whose 4 largest tables contain between 4 million and 10 million rows each and about 15 fields each, with indexes on different field types (numbers, ...
10
votes
3answers
10k views

MySQL table_cache and Opened_tables

I have seen people use the comparison of Open_tables and Opened_tables to assess whether the table_cache is too small in MySQL. However, I believe that Opened_tables is cumulative across uptime, so ...
5
votes
1answer
6k views

How do you increase MySQL performance using current server resources?

I have a MySQL database and some of my queries became slow. Query time is not stable. Most of the queries are fast, but some of them (may be that reads and returns less data) take long time. I know ...
4
votes
2answers
838 views

Creating partitions on a production database

I have a production MySQL 5.1 database that is running well but I want to improve query performances. I have never used Partitions and just going through the manuals. I have two tables that involve a ...