`JedisClusterHashCommands.hStrLen()` should calls `hstren` on `JedisCluster` object

[DonalEvans]

The JedisClusterHashCommands.hStrLen() method does not use the getCluster() method to allow the command to be executed correctly in Cluster mode:

	@Nullable
	@Override
	public Long hStrLen(byte[] key, byte[] field) {
		return Long.class.cast(connection.execute("HSTRLEN", key, Collections.singleton(field)));
	}

For comparison, all other methods in the class use connection.getCluster() e.g.:

	@Override
	public Map<byte[], byte[]> hGetAll(byte[] key) {

		Assert.notNull(key, "Key must not be null!");

		try {
			return connection.getCluster().hgetAll(key);
		} catch (Exception ex) {
			throw convertJedisAccessException(ex);
		}
	}

This can lead to exceptions in the client if servers are shutdown during execution of the command, instead of retying on a different server as is expected.

This bug appears to have been introduced with this commit and is still present in the latest unreleased version.

[mp911de]

Do you want to submit a pull request to fix the problem?

[DonalEvans]

Do you want to submit a pull request to fix the problem?

I'm afraid I don't have a lot of spare time to work on this, and my familiarity with the Spring Data Redis codebase and testing is almost nonexistent, so I don't feel that I would be a good choice to implement this fix.