# Innodb\_log\_file\_size Parameter Appropriate Size For Master and Slaves mysql 5.6 **URL:** \ **Category:** Percona Server for MySQL 5.6\ **Created:** [August 2, 2023, 12:50pm UTC](https://forums.percona.com/t/innodb-log-file-size-parameter-appropriate-size-for-master-and-slaves-mysql-5-6/24137 "2023-08-02T12:50:05Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![tamoor\_ali](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/tamoor_ali/32/12036_2.png) [@tamoor\_ali](https://forums.percona.com/u/tamoor_ali)\ **Post date:** [August 2, 2023, 12:50pm UTC](https://forums.percona.com/t/innodb-log-file-size-parameter-appropriate-size-for-master-and-slaves-mysql-5-6/24137/1 "2023-08-02T12:50:05Z")
I have a Scenario to set inndb\_log\_file\_size as some cron jobs and services are running on Master and Slaves(Select relevant Data From Slave and update it on Master) So in That Scenario If We Calculate Innodb\_log\_file\_size through the Following formula SHOW ENGINE INNODB STATUS\G; SELECT SLEEP(60); SHOW ENGINE INNODB STATUS\G; then it usually exceeds 9 GB on contrary its 2GB in my. cnf. On the Other hand, The inndb\_buffer\_pool\_size is almost 80 GB. Some fox says that inndb\_log\_file\_size should be 25 percent of inndb\_buffer\_pool\_size. What Does it impact on the slave? In slaves inndb\_log\_file\_size is almost 268 Mb does it impact slave performance? What should be the slave size ? is it the same like master Does SQL? ---
**Author:** ![matthewb](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/matthewb/32/34_2.png) [@matthewb](https://forums.percona.com/u/matthewb)\ **Post date:** [August 2, 2023, 3:01pm UTC](https://forums.percona.com/t/innodb-log-file-size-parameter-appropriate-size-for-master-and-slaves-mysql-5-6/24137/2 "2023-08-02T15:01:21Z")
Hello @tamoor_ali, `inndb_log_file_size` should be large enough to handle approximately 1 hour’s worth of transactions. If this is too small, then InnoDB will experience micro-stalls while it aggressively flushes dirty pages to disk. Having it too large really only impacts crash recovery, if that should happen. 1 hour has been deemed “plenty of time” for InnoDB to flush everything, even on the busiest of systems. > [@tamoor\_ali](#): > > We Calculate > Innodb\_log\_file\_size through the Following formula That is the correct formula and it should be executed during the busiest time of your DB. > [@tamoor\_ali](#): > > its 2GB in my. cnf. Update your my.cnf to match formula. Shut down mysql, remove the log files, then restart mysql. InnoDB will rebuild new ones with larger size. > [@tamoor\_ali](#): > > What Does it impact on the slave? Replica typically should match source. (slave and master are old terms that are no longer used) Run the same formula on replica and use that in replica my.cnf