Re: Problem with slow localhost connections

[Allan Streib <astreib@indiana.edu>]

A bit more info -- running ldapsearch with -d -1 and simple bind (-x):

ldap_bind_s
ldap_simple_bind_s
ldap_sasl_bind_s
ldap_sasl_bind
ldap_send_initial_request
ldap_new_connection
ldap_int_open_connection
ldap_connect_to_host: localhost

** here is the delay.  Nothing from tcpdump yet.  After 6 - 10
seconds, logging proceeds with the following, and I also see activity
on lo from tcpdump.

ldap_new_socket: 3
ldap_prepare_socket: 3
ldap_connect_to_host: Trying 127.0.0.1:389
ldap_connect_timeout: fd: 3 tm: -1 async: 0
ldap_ndelay_on: 3
ldap_is_sock_ready: 3
ldap_ndelay_off: 3
.
.
.
 ** everything normal after this ...

On Fri, 6 Dec 2002, Allan Streib wrote:

> I don't know if this is an LDAP problem or a kernel/networking
> problem, but -- I am running OpenLDAP 2.0.23 on RedHat Linux 7.3,
> kernel 2.4.18-17.7.x
>
> I have suddenly started seeing delays of up to 10 seconds when doing
> an ldapsearch on localhost, after being up and running for over two
> weeks with no problems at all.  It is intermittent, but more often
> than not.  The activity in the slapd log shows that the delay appears
> to be outside of ldap, by which I mean that once the connection is
> logged everything happens very quickly.  Also watching netstat I don't
> see the localhost ldap connection for some seconds when this happens.
>
> In one case ran tcpdump on the lo interface and saw no activity for
> apoximately 6 seconds after I initiated the ldapsearch command.
>
> I have not ever seen this behavior using other network interfaces
> (e.g. eth0).
>
> All this leads me to belive I have a networking bug related to
> localhost but I thought I would post it in case anyone else has run
> into this and can confirm or suggest other things I can look at.
>
> Allan
>
>