DB Cache Sync

DB Cache Sync reads MySQL binlogs asynchronously using go-mysql/canal and updates Redis cache based on database changes (Insert/Update/Delete).

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Features

• Read MySQL binlog events (insert, update, delete)
• Update Redis cache asynchronously
• Auto-reconnect on MySQL/Redis failures
• Lightweight

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Requirements

• Go 1.20+
• MySQL (Binlog enabled, Row format)
• Redis server

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Installation

git clone https://your-repository-link/db-cache-sync.git
cd db-cache-sync
go mod tidy
go run main.go

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Configuration

Edit main.go to update your database and Redis connection settings:

cfg.Addr = "host:port"
cfg.User = "your_mysql_user"
cfg.Password = "your_mysql_password"
cfg.Flavor = "mysql"
cfg.ServerID = 1001 // random unique number

// Redis config
redisClient = redis.NewClient(&redis.Options{
    Addr:     "localhost:6379",
    Password: "",
    DB:       0,
})

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MySQL Binlog Settings (important)

Make sure MySQL server is configured properly:

SHOW VARIABLES LIKE 'binlog_format'; -- Should be ROW
SHOW VARIABLES LIKE 'binlog_row_image'; -- Should be FULL

If not, set in your my.cnf:

[mysqld]
log-bin=mysql-bin
server-id=1
binlog-format=ROW
binlog-row-image=FULL

Restart MySQL after changes.

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Usage

Simply run:

go run main.go

The service will listen to binlogs and update Redis automatically.

Example Redis Key format:

• Insert: cache:{table_name}:{primary_key} → JSON value
• Update: cache:{table_name}:{primary_key} → updated JSON
• Delete: Redis key deleted

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Error Handling

If MySQL dump fails with:

Couldn't execute 'SET SQL_QUOTE_SHOW_CREATE=1...': Variable 'sql_mode' can't be set...

Solution:
Set DumpExecPath to empty and skip initial snapshot in code:

canalCfg.Dump.ExecutionPath = ""
canalCfg.Dump.TableDB = ""

You can also disable Dump mode entirely if binlog position is already known.

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Libraries Used

• go-mysql/canal
• go-redis/redis

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License

This project is open-sourced under the MIT license.