Making Super Fast MySQL Database with RAM Disk and Master-Master Replication for Data Integrity

I am planning to create ram disk and use it as for mysql server will have all mysql files in it so read write happens in ram disk.
Also to maintain persistence I will do remote mysql master master backup.
Is it a good idea ?
Will there be performance issue can I get ram read write in main mysql server ?
How would you approach this to get database speed really high and maintain backup so no data loss

ChatGPT:

Your idea of using a RAM disk for MySQL combined with master-master replication for persistence can deliver blazing fast performance, but there are key considerations to ensure stability, reliability, and long-term success. Here’s how I’d approach it:

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1. Setting Up the RAM Disk for MySQL

Using a RAM disk can significantly boost MySQL’s read/write performance since RAM offers ultra-fast I/O speeds compared to SSDs or HDDs.

Steps for RAM Disk Setup (Ubuntu 22.04):

mkdir /mnt/ramdisk
mount -t tmpfs -o size=4G tmpfs /mnt/ramdisk

• Adjust size= based on available RAM.
• Add this to /etc/fstab for automatic mounting on reboot:

tmpfs /mnt/ramdisk tmpfs rw,size=4G 0 0

Move MySQL Data Directory to RAM Disk:

1. Stop MySQL: systemctl stop mysql
2. Copy data to RAM disk: cp -R /var/lib/mysql/* /mnt/ramdisk/
3. Update MySQL config:
   In /etc/mysql/mysql.conf.d/mysqld.cnf
datadir = /mnt/ramdisk
4. Start MySQL: systemctl start mysql

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2. Master-Master Replication for Persistence

Since RAM is volatile, replication is crucial to prevent data loss.

• Server A (Primary RAM Disk) → Server B (Backup with Persistent Storage)
• Use semi-synchronous replication for improved data integrity.

Steps for Master-Master Setup:

1. On both servers, add in mysqld.cnf:
   server-id = 1 # Change to 2 on the second server
   log_bin = mysql-bin
   binlog_do_db = your_database
   
2. On Server A (RAM Disk), create a replication user:
   CREATE USER 'repl'@'%' IDENTIFIED BY 'password'; GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%';
   
3. On Server B, run:
   CHANGE MASTER TO MASTER_HOST='Server_A_IP', MASTER_USER='repl', MASTER_PASSWORD='password', MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS= 154; START SLAVE;
   
4. Repeat the process for Server A to point back to Server B.

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3. Recommended Optimizations for Maximum Speed

✅ Increase InnoDB Buffer Pool Size (to fit most of your data in memory)

innodb_buffer_pool_size = 2G

✅ Tweak tmpfs Mount Options

• Use noatime to reduce write overhead.

mount -t tmpfs -o rw,noatime,size=4G tmpfs /mnt/ramdisk

✅ Tune MySQL Settings for Performance

innodb_log_file_size = 512M
innodb_flush_log_at_trx_commit = 0
sync_binlog = 0

✅ Reduce Disk Writes

• Set innodb_flush_log_at_trx_commit = 2 (less durable but faster).

✅ Optimize Table Indexing

• Ensure key fields have proper indexing for faster lookups.

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4. Backup Strategy

To ensure no data loss:

• Use mysqldump or xtrabackup to sync data to persistent storage at regular intervals.
• Automate backups every 5-10 minutes using cron:

*/5 * * * * /usr/bin/mysqldump -u root -p'your_password' your_database | gzip > /backup/mysql_backup_$(date +\%F_\%T).sql.gz

• Store backups on both the local persistent disk and a remote server for redundancy.

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5. Potential Risks & Solutions

✅ Power Loss Risk: RAM is volatile. Ensure replication + frequent dumps.
✅ Memory Pressure Risk: If RAM is overloaded, MySQL performance may suffer. Monitor with htop or free -h.
✅ Crash Recovery Risk: Enable binlogs and point-in-time recovery.

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Ideal Setup for Peak Performance and Safety

✅ RAM Disk for MySQL data
✅ Master-Master replication for redundancy
✅ Automated backups every 5-10 minutes
✅ Tweaked MySQL settings for faster memory utilization

This combination should give you lightning-fast performance while minimizing data loss risk.