Question

I am running some map reduce jobs via the PHP client library as such:

$m = new Mongo(MY_CONN_STRING);
$db = $m->selectDB(MY_DB);
// run the map reduce function inside the DB
$db->command(array(
    "mapreduce" => "CBD", 
    "map" => $map,
    "reduce" => $reduce,
    "query" => $filter,
    "out" => $out));

I would like to return control to the thread straight away and let the map reduce command complete in the background, however at present MongoDB::command() is blocking.

Any ideas?

Answer 1

Not really. You could set a client-side timeout so that the command will immediately time out and then check the $out collection later, but you cannot ever retrieve the command result (or see if it succeeded).

Forcing an immediate timeout would look something like:

try {
    $db->command(array(...), array("timeout" => 1)); // timeout after 1ms
}
catch (MongoCursorTimeoutException $e) {
    // do nothing
}