Questions tagged [percona]

Percona : MySQL open source fork with performance improvements

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27
votes
2answers
9k views

How do I properly perform a MySQL bake-off?

I want to performance test (aka bake-off) MySQL server rpm against some other forks such as Percona server, MariaDB, and possibly some others. I'm hoping that by asking this question I can better ...
22
votes
3answers
44k views

Should a MySQL replication slave be set to read only?

I've got replication running on Percona Server 5.5 by following this guide and wondered if I should add read-only=1 to my slave's my.cnf to make it read only? The guide sets up replication for the ...
22
votes
2answers
20k views

Percona vs MySQL

What is Percona? How does it differ from MySQL? When should we consider switching (or upgrading) from stock MySQL to Percona? To add some specifics in our situation we almost exclusively use ...
12
votes
1answer
42k views

Why default character_set_server is latin1?

I am using MySQL 5.5 and when I show variables about charset, I have +--------------------------+----------------------------+ | Variable_name | Value | +--------------...
11
votes
1answer
5k views

What is the difference between XtraBackup and rsync?

Yes, I'm going to run strace on them both... However, I would like to know ... What is XtraBackup is doing over and above rsync -ac src dest ? What's so special about XtraBbackup ? How is XtraBackup ...
8
votes
1answer
25k views

MySQL requires FORCE INDEX on huge table and simple SELECTs

We have an application which stores articles from different sources in a MySQL table and allows users to retrieve those articles ordered by date. Articles are always filtered by source, so for client ...
7
votes
2answers
35k views

query_cache_type = 0 vs query_cache_type = 1

Recently, I moved from standard MySQL to Percona, and used the Percona Wizard to generate my.cnf. However, I can see that, by default, the generated settings for my.cnf use query_cache_type = 0. (...
7
votes
3answers
2k views

How to run OPTIMIZE TABLE on a 3-node cluster?

I've my hands on a 3-node Percona XtraDB Cluster where, according to mysqlcheck, some tables are corrupted (some indexes contain the wrong number of entries): mydb.mytable Warning : InnoDB: Index '...
7
votes
2answers
3k views

Investigate peak in MySQL throughput

Recently one of our servers has ran out of memory and crashed. After reviewing the munin graphs, it appears that the only metric (other than memory usage) that peaked just before the crash was the ...
6
votes
2answers
5k views

Scaling Percona datacenters: setup and replication

Since our startup has taken off nicely we are now meeting with some of those issues that you always assumed would NEVER effect you. We have already scaled alot of our application stack: we offloaded ...
6
votes
2answers
32k views

Transaction speed benchmarks for mySQL v5.6 replication - seems very slow

I'm trying to select the best configuration for our new infrastructure but got a bit confused about the results. I used sysbench v0.5 for the tests: prepare data sysbench --test=/usr/share/doc/...
6
votes
2answers
677 views

COMMIT on top of the pt-query-digest output

I've been optimizing my MySQL server and after tweaking a few queries, I ended up with the COMMIT item on top of the pt-query-digest output, as shown in the extract below: # 322s user time, 770ms ...
5
votes
1answer
901 views

Percona MySQL 5.5 Unique key is duplicated

I'm totally out from ideas, so maybe somebody else could answer my question. We have a MySQL 5.5 server from Percona with high traffic. The application is in PHP and writes always to master. We have ...
5
votes
2answers
601 views

Is there a way to create a MySQL/Percona Slave without using a dump?

I haven't been able to find anything so I'm sure the answer is no, what are you, a noob? but I feel the need to ask anyway :) Is there a simple utility that would allow a new slave server to be ...
5
votes
1answer
270 views

MongoDB Migrating away from RocksDB to WiredTiger

We have been working for some time with RocksDB as our engine and we are now trying to migrate to WiredTiger. We have some pretty big databases around 4~12 TB of data and according to the process ...
5
votes
1answer
4k views

Mysql Cluster vs Percona/Maridb Cluster [closed]

We want to setup a mysql cluster with master-master sync replication, to provide HA so that one db for write from one app, other for write from other app. It is a webapp with high write and medium ...
5
votes
1answer
476 views

MySQL Partitions with Partition limit

I have a partitioned table on the basis of the Primary key having 1.5 Billion rows in it. But when I check the .ibd files only 80 ibd show in GB's whereas 120ibd shows 1MB file. I would like to know ...
4
votes
2answers
1k views

How does MySQL manage its memory with regards to indexes?

To start off, the reason I'm asking this, is because I feel I have a database that - according to my own estimates - should have been killing the disks with massive I/O, because of indexes not fitting ...
4
votes
1answer
3k views

Percona: Backup preparation doesn't work (“cannot open ./xtrabackup_logfile”)

I've created a MySQL backup with PerconaXtrabackup tool via (thanks to this guide): innobackupex --user=backupmysqluser --password=xyz --compress --stream=xbstream ./ > /var/backups/db/firstBackup....
4
votes
1answer
2k views

Active-active Cluster In MySQL

I'm planning to go for a 3-node active-active MySQL cluster which will not have more 100 databases. Many experts here have already told there are issues with MySQL 5.6 and 5.7 where circular ...
4
votes
3answers
6k views

What should I set my table_definition_cache to?

I just discovered table_definition_cache and I am trying to decide what to set it to. I am messing with my config because of performance issues. On one server I have 36599 tables and when I run SHOW ...
4
votes
2answers
3k views

Column cannot be converted from type 'int' to type 'bigint(20) unsigned'?

I have a Percona MySQL cluster, with a master and a few slaves. Each of them is running "Ver 14.14 Distrib 5.5.40-36.1" of MySQL. Replication is row based. I ran an alter query on one of the tables ...
4
votes
2answers
2k views

Percona Toolkit Installation Error

[root@localhost ~]# rpm -ivh percona-toolkit-2.2.7-1.noarch.rpm error: Failed dependencies: perl(DBD::mysql) >= 1.0 is needed by percona-toolkit-2.2.7-1.noarch perl(Time::HiRes) is needed by ...
4
votes
1answer
5k views

How to prevent “ibdata files do not match the log sequence number”?

I am dealing with a very large set of databases that are all innodb. I've enountered this on mysql restart too many times for my comfort: ibdata files do not match the log sequence number But I've ...
3
votes
2answers
6k views

What is the optimal solution for storing real time time-series in MariaDB / MySQL?

Use case: A measurement creates a given number of images. For each image we need to store a small set of quality indicators (floats, doubles) along with an image integer [1 ...N], a timestamp and one ...
3
votes
3answers
1k views

Is it possible to pass parameters to pt-table-checksum using an options file?

We're using Percona's pt-table-checksum for MySQL replication integrity check. Is it possible to pass some or all of the options using some sort of configuration file? For instance, can we write the ...
3
votes
3answers
208 views

MySQL can take more than an hour to start

I have a mysql (Percona) 5.7 instance with over 1Million tables. When I start the database, it can take more than an hour to start. Errorlog doesn't show anything, but when I trace mysqld_safe, I ...
3
votes
1answer
668 views

Galera cluster into Google cloud platform

We have a galera cluster with 3 nodes, on 3 different physical machines but all located in the same datacenter. From what I understood, the reason they deployed this in the past was to increase ...
3
votes
2answers
374 views

How to optimize this specific MySQL query which examines 2.84M rows and 29.49k InnoDB distinct pages

I am trying to figure out why one query need ~5 seconds to be completed and how to optimize it. Here is what information I gathered so far: 1. EXPLAIN statement for the query: EXPLAIN EXTENDED ...
3
votes
1answer
1k views

MySQL Replication query - Primary key need

I have few doubts regarding MySQL replication (Master-Slave). Is it mandatory for a table to have primary query for replication to function properly? Referring this Percona link for the above ...
3
votes
1answer
2k views

How to migrate from MySQL to MariaDB or Percona with minimum downtime?

I want to migrate my MySQL 5.1 database to one of these databases: MariaDB, PerconaDB or MySQL 5.6 Is there any way to do this operation with no downtime or with minimum downtime possible? How? The ...
3
votes
2answers
592 views

How to make TokuDB engine on Percona delete faster

I've done some reading on the percona website, most notably MySQL Partitioning: A Flow Chart where they recommend TokuDB as a solution to faster(er) deletes over innoDB rather than partitioning. I've ...
3
votes
2answers
1k views

How pt-online-schema-change ensures consistency during data copy

I have read pt-online-schema-change documentation and understood that it works by creating triggers and copying data in chunks with in chunk-time seconds(0.5 seconds in default) Let us consider this ...
3
votes
2answers
3k views

Percona XtraDB Cluster and MySQL Replication

I've setup a 3-node multi master replication with percona xtradb cluster, it works perfectly. Now I've tried to add some read-only slaves setting up replication as usual but it seems the binlog doesn'...
3
votes
1answer
418 views

Why are my queries getting really slow?

I own a WordPress installation, and Updated to 3.4.1. After the upgrade, I experienced a very strange slow-down. After all, I used the define('SAVEQUERIES', true); in my wp-config.php with ...
3
votes
1answer
7k views

Fixing tables out of sync as reported by pt-table-checksum, pt-table-sync is not working

I have several tables being reported by pt-table-checksum with CRC_DIFF between my master and slave servers using the following commands: $ pt-table-checksum h=master,u=user,p=password --empty-...
3
votes
1answer
2k views

Percona crash after running for some time [closed]

my mysql db crash after running for some time. MySQL version is *************************** 1. row *************************** Variable_name: innodb_version Value: 5.7.10-3 ******************...
3
votes
1answer
5k views

MySQL slave taking too long on “Queueing master event to the relay log”

I have two mysql mysql slave servers. The DB version is: mysql> show variables like '%version%'; +-------------------------+-----------------------------------------------------+ | Variable_name ...
3
votes
1answer
212 views

Backup and off-site restore setup

I've been reading a lot of threads about different backup options for MySQL and was hoping for some more insight so I can settle on one. Our current situation is ~100 GB of InnoDB and MySAM data in ...
3
votes
2answers
2k views

Upgrading to MySQL 5.6, benefits to switching to GTID replication?

We have the most basic of MySQL replication setups, a single Master doing statement-based replication to a single Slave, a 90/10 mix of innodb/myisam tables. Both run Percona MySQL 5.5 at the moment ...
3
votes
1answer
614 views

Percona xtrabackup transaction log corrupted

I am attempting to prepare and restore a full backup taken through xtrabackup via a scheduling script called surrogate. I have tarred and gzipped the backup, transferred to a local machine running ...
3
votes
1answer
623 views

Tokudb 5.7 [Warning] The partition engine is deprecated and will be removed in a future release

I am running upgrade from Tokudb 5.6.30 to 5.7.17 (Percona distribution) and I am getting this warning [Warning] The partition engine, used by table ‘my_table’, is deprecated and will be removed in ...
3
votes
1answer
2k views

Percona Node fails to join: Operation not permitted

Joining a new Percona node fails with: 130521 7:15:44 [Warning] WSREP: Failed to prepare for incremental state transfer: Local state UUID (00000000-0000-0000-0000-000000000000) does not match group ...
3
votes
1answer
346 views

innobackupex is failing while exporting backup

I am using perl script which is working fine in one of my other box which used to take individual schema backups & finally take all schema together using percona innobackupex. I have following ...
3
votes
1answer
2k views

Does this make my XtraDB Cluster hang?

After seeing the following in the error log on the second node: 121003 7:16:06 [Note] WSREP: Member 0 (joiner) synced with group. 121003 7:16:06 [Note] WSREP: Shifting JOINED -> SYNCED (TO: 0) ...
3
votes
1answer
3k views

MySQL Handler_read_rnd_next == tablescans without indexes?

I am in the process of tuning our Percona 5.5 server, and have been using percona's tools to plot our database's performance. In the MySQL Handlers Plot, i have been noticing alot of "...
3
votes
0answers
159 views

TokuDB/Percona - Insert Performance worse as table grows

We have a bunch of existing servers which run just fine, inserting our thousand rows/second, but the new batch just will not do it. As the day goes on and the table grows, it gets slower and slower, ...
2
votes
2answers
6k views

How to set MySQL binlog retention in hours?

I'm in a situation where the MySQL log partition is being filled in less than a day. I can't disable binlogs, since I need them for replication. I know I can set log retention but that accepts days, ...
2
votes
3answers
3k views

What is an “empty query” in information_schema.CLIENT_STATISTICS?

The client stats table has an "empty queries" column. What does that mean? Simple googling just tells me "The number of times this client's connections sent empty queries to the server." /facepalm
2
votes
3answers
1k views

HA - MySQL Master Master replication - Duplicate entry errors

I am running Percona MySQL 5.5.39 on two masters with keepalived monitoring a VIP which will failover to the standby master if the primary master goes dark. While testing the fault tolerance of my ...