Sphinx searchd error: Query failed: expected searchd protocol version 1+, got version '0'

I've recently installed Sphinx search on an EC2 instance running CentOS. Using search from the command line works fine and I've created a valid index of documents. When I try to access the php api through the searchd daemon, however, I get th开发者_如何学Pythone following error:

Query failed: expected searchd protocol version 1+, got version '0'

Here is the searchd config info from sphinx.conf:

searchd
{
    listen          = /var/run/searchd.sock
    log             = /usr/local/sphinx/var/log/searchd.log
    query_log       = /usr/local/sphinx/var/log/query.log
    read_timeout    = 5
    max_children    = 30
    pid_file        = /usr/local/sphinx/var/log/searchd.pid
    max_matches     = 1000
    seamless_rotate = 1
    preopen_indexes = 1
    unlink_old      = 1
    workers         = threads # for RT to work
}

I cannot resolve this. Any help would be appreciated.

EDIT 1: I have started the searchd daemon.

There is missmatch with API and searchd versions. It could be better to use same API as searchd.

The version of you PHP api is lower than searchd. Just try the same client api as searchd.

It's a performance issue most probably. When searchd is unable to respond to too many requests you will get that error.