Re: timeout in LDAP access

[Denis Excoffier <Denis.Excoffier@free.fr>]

On 2014-06-25 23:13 Corinna Vinschen wrote:
> 
> You asked for errors being propagated up the chain to the
> getpwent/getgrent calls and that's exactly what happens now.  There are
> a lot of LDAP error codes.  How is Cygwin supposed to handle every one
> of them?  Do we need a list of ignorable and non-ignorable error codes?
I don’t know. IMHO:
- a server which is down can be ignored (unless explicitly requested)
- a timeout, when some output has already been received, must be reported
- all servers should be treated independently since they are independent
For the time being, i have added LDAP_SERVER_DOWN in map_ldaperr_to_errno
at the same place as LDAP_SUCCESS.
> 
>> Also, there was a large delay (more than 2 min, say at least 8 minutes) between
>> the end of output and the end of getent. I got one single system_printf
>> message (see above).
> 
> I can't observe this.  It needs debugging in your environment so I know
> which part of the source is responsible for this delay under what
> circumstances.
I forgot to test it again. I’ll do it soon.
> 
>> More than that, i added system_printf("starting open in domain %W", domain)
>> immediately at the beginning of cyg_ldap::open, and run ‘getent passwd’ now during
>> one minute (wait 60s, then Control-C). I got 1080 ‘starting open in domain (null)’
>> messages on stderr and 1016 normal passwd entries on stdout. The discrepancy
>> 1016 vs 1080 is ok because stdout was not properly flushed out.
> 
> 60 seconds for 1016 user entries?  That sounds incredibly slow.
I’m pretty sure that this is due to the non-buffering
of stderr. In fact, system_printf() is incredibly slow ;-)

>> - there are as many open() calls as passwd entries in the output?
> 
> The open function is called for every account, but that doesn't mean it
> really needs opening.  That's what the early return is for.  The code
> starts like this:
> 
>  [...]
> 
> Did you add the system_printf before the "/* Already open? */" comment,
> by any chance?
You’re right. It was before. Now i have it after and there is only one
such message for the primary domain.

However, for the non-primary domains the result is the same: i get as
many cyg_ldap::open()s as accounts. Even more strange, for all these open’s
(except the first one) the domain variable is printed as (null). Perhaps
something uncontrolled within pg_ent::enumerate_ad()? Simple suggestion, i
was not able to understand the logic there.

> 
> Corinna
Denis.


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