MySQL
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* De-pool another slave from the same cluster, which will be used as the base. | * De-pool another slave from the same cluster, which will be used as the base. | ||
| + | * Clean up the existing slave from replication errors | ||
* Install required packages on the new slave server | * Install required packages on the new slave server | ||
* Tweak the configuration file of the new slave | * Tweak the configuration file of the new slave | ||
| − | |||
* Binary copy of relevant data from existing slave to new slave | * Binary copy of relevant data from existing slave to new slave | ||
* Add both servers to the pool | * Add both servers to the pool | ||
* Cross fingers and make sure everything works... | * Cross fingers and make sure everything works... | ||
| + | |||
| + | == De-pooling / Clean up / Shutdown == | ||
| + | |||
| + | * The file we are going to be working on is: /home/wikipedia/common/wmf-deployment/wmf-config/db-pmtpa.php | ||
| + | * In this file, find the cluster you are working with. In this case, we want to add a slave to the commons db, ergo the cluster is: s2commons | ||
| + | * The 'sectionLoads' array will show the current members of the cluster. The FIRST member is ALWAYS the MASTER! In this case, the master would be db13. | ||
| + | * Pick a slave. For this we will use db3, and we will be working on installing db8 as the new slave. | ||
| + | * De-pool db3 so that we can copy data from it when the data is not changing. In the same array, comment out db3, and sync-file db-pmtpa.php. | ||
| + | * Clean up the slave by running reset-mysql-slave db3.pmtpa.wmnet on Zwinger | ||
| + | * Shut down mysqld on db3 and wait for the shutdown to complete (can take up to 1/2 hour). | ||
| + | |||
| + | == Installing required packages on the "new" slave: == | ||
| + | |||
| + | * On db8 (our new slave server), install the following: | ||
| + | * * wikimedia-mysql4 (our default mysql server package) | ||
| + | * * pv (to monitor the data transmission as described below) | ||
| + | |||
| + | == Tweak configuration file on the new slave: == | ||
| + | |||
| + | * edit the /etc/my.cnf file and change the line: | ||
| + | |||
| + | <code> | ||
| + | #id = 1 + zero-filled last 4 digits of internal IP | ||
| + | server-id = 100241 | ||
| + | </code> | ||
| + | |||
| + | == Binary copy: == | ||
| + | |||
| + | As usual, there is more than one way to do it. However the most efficient way that was pointed out to me is to use nc+tar combination to transfer everything from one slave to the other. You could just as well use mysql-dump or mydumper, scp and then re-import everything, but it is a lot more time-consuming. | ||
| + | |||
{{PD}} | {{PD}} | ||
[[Category:Software]] | [[Category:Software]] | ||
Revision as of 17:09, 11 August 2009
- MySQL server tools - setup outline, quick howtos
- http://wp.wikidev.net/Special:Search?search=mysql&fulltext=Search
Contents |
Installing a new Slave host
In this section, I will describe the steps to take in order to create a new slave from scratch.
To summarize the steps:
* De-pool another slave from the same cluster, which will be used as the base. * Clean up the existing slave from replication errors * Install required packages on the new slave server * Tweak the configuration file of the new slave * Binary copy of relevant data from existing slave to new slave * Add both servers to the pool * Cross fingers and make sure everything works...
De-pooling / Clean up / Shutdown
- The file we are going to be working on is: /home/wikipedia/common/wmf-deployment/wmf-config/db-pmtpa.php
- In this file, find the cluster you are working with. In this case, we want to add a slave to the commons db, ergo the cluster is: s2commons
- The 'sectionLoads' array will show the current members of the cluster. The FIRST member is ALWAYS the MASTER! In this case, the master would be db13.
- Pick a slave. For this we will use db3, and we will be working on installing db8 as the new slave.
- De-pool db3 so that we can copy data from it when the data is not changing. In the same array, comment out db3, and sync-file db-pmtpa.php.
- Clean up the slave by running reset-mysql-slave db3.pmtpa.wmnet on Zwinger
- Shut down mysqld on db3 and wait for the shutdown to complete (can take up to 1/2 hour).
Installing required packages on the "new" slave:
- On db8 (our new slave server), install the following:
- * wikimedia-mysql4 (our default mysql server package)
- * pv (to monitor the data transmission as described below)
Tweak configuration file on the new slave:
- edit the /etc/my.cnf file and change the line:
- id = 1 + zero-filled last 4 digits of internal IP
server-id = 100241
Binary copy:
As usual, there is more than one way to do it. However the most efficient way that was pointed out to me is to use nc+tar combination to transfer everything from one slave to the other. You could just as well use mysql-dump or mydumper, scp and then re-import everything, but it is a lot more time-consuming.
