When creating a Redis KVStore it tests the connection using Redis' PING command.
Due to the simple API of the library, the Redis adapter only supports reading/writing byte arrays. The behavior when reading any other Redis type (e.g. a list or set) is undefined.
Redis doesn't have actual transactions, so this library simulates them by using the MULTI/EXEC/DISCARD commands.
That way all commands are guaranteed to be executed atomically.
As a consequence, a value that hasn't been committed yet can't be read. In other words, don't try to read a value from a key that was written to in the same transaction. Subsequently, changes from other writers (from the same process or remote) are reflected immediately in the current transaction: if a key is read twice, there's no guarantee the returned value will be equal.
If the application requires exclusive write access to a store it can lock the database, to assert there are no other active writers:
store.Write(func (tx stoabs.WriteTx) error {
// do something with tx
}, stoabs.WithWriteLock())The lock is released when the transaction is committed or rolled back.
The lock is subject to the prefix (CreateRedisStore(prefix string, ...)) the store was created with, meaning other stores with the same prefix will have the same lock.
Redis locks are implemented using (Redsync)[https://github.com/go-redsync/redsync].
- Clustering