Flushing All Memcached Keys in Golang (Detailed Guide w/ Code Examples)

Use Case(s)

Flushing all keys from Memcached is typically used when you want to invalidate all cache data. This can be useful during situations like:

• Debugging issues related to caching.
• A significant update in the application that requires a clean slate of cached data.
• Periodic cache refreshes to ensure data relevance.

Code Examples

For these examples, we will use the gomemcache package which provides a memcached client for Go.

Firstly, import the required package and connect to your memcached server:

package main

import (
	"fmt"
	"github.com/bradfitz/gomemcache/memcache"
)

func main() {
    mc := memcache.New("localhost:11211")
}

To flush all keys, use the FlushAll function. It doesn't need any arguments.

err := mc.FlushAll()
if err != nil {
    fmt.Println(err)
} else {
    fmt.Println("All keys flushed successfully.")
}

This will delete all the keys from your memcached server.

Best Practices

While flushing all keys from Memcached can be helpful, it should be done with caution due to the following reasons:

• It can lead to a temporary increase in load on your database as all requests will go directly to the database till the cache is warmed up again.
• It may cause unnecessary invalidation of all data even if only a subset needs to be updated.

Common Mistakes

• Not handling errors returned by the FlushAll function. Always handle potential errors to know whether the operation was successful or not.
• Frequent use of FlushAll. This circumvents the benefits of caching and can put unnecessary load on the database.

FAQs

Q: Does FlushAll operation delete keys instantly?

A: The flush operation doesn't remove items immediately. It simply sets a time after which all current items are invalidated.

Q: Can I undo the FlushAll operation?

A: No, once executed, the FlushAll operation cannot be undone. All the keys in the cache are invalidated.