[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: deferring operation: pending operations

Ben Beuchler wrote:
On 4/7/07, Howard Chu <hyc@symas.com> wrote:
Ben Beuchler wrote:
Apr  5 11:32:52 swizzle slapd[1626]: connection_input: conn=6232680
deferring operation: pending operations

What does "deferring operation: pending operations" actually indicate?
It means that an operation that was just received on that connection has
been deferred, because there are other operations ahead of it that are
still pending. I.e., there's a bunch of operations on that connection
waiting to execute, and the newcomer is last in line.

Hmmm. That particular connection rarely makes more than a couple search or bind requests per second. Well within what OpenLDAP should be able to handle on a nice, fast server like this. Is there a class of mistakes that the client could be making to cause operations to queue up like this?

The only time I've seen this occur on a frequent basis is with poorly written clients like Sendmail, which sends off a stream of a hundred or so search requests on a connection before it checks for any replies. The problem there is that the search replies build up in the network and socket buffers and once the socket buffer gets full we can't send anything else. At that point we stop executing operations on the connection; we just wait for the client to drain it.

  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP     http://www.openldap.org/project/