[Freeipa-devel] slow response
Loris Santamaria
loris at lgs.com.ve
Wed Aug 1 20:49:13 UTC 2012
El mié, 01-08-2012 a las 13:50 -0600, Rich Megginson escribió:
> On 08/01/2012 01:34 PM, Loris Santamaria wrote:
> > El mié, 01-08-2012 a las 09:58 -0600, Rich Megginson escribió:
> >> On 08/01/2012 09:20 AM, Loris Santamaria wrote:
> >>> El mié, 01-08-2012 a las 10:35 -0400, Simo Sorce escribió:
> >>>> On Tue, 2012-07-31 at 08:49 -0700, Stephen Ingram wrote:
> >>>>> On Tue, Jul 31, 2012 at 1:39 AM, Petr Spacek<pspacek at redhat.com> wrote:
> >>>>>> On 07/31/2012 12:27 AM, John Dennis wrote:
> >>>>>>> What is taking so long with session bookkeeping? I don't know yet. I would
> >>>>>>> need more timing instrumentation. I will say when I looked at the
> >>>>>>> python-krb5
> >>>>>>> code (which we use to populate the ccache from the session and read back
> >>>>>>> to
> >>>>>>> store in the session) seemed to be remarkably inefficient. We also elected
> >>>>>>> to
> >>>>>>> use file based ccache rather than in-memory ccache (that means there is a
> >>>>>>> bit
> >>>>>>> of file-IO occurring).
> >>>>>> A note regarding python-krbV:
> >>>>>> I used python-krbV extensively in my thesis for KDC stress test. Python-krbV
> >>>>>> can obtain several thousands of TGTs per second (even with ccache in a
> >>>>>> file). AFAIK VFS calls are not done synchronously. But others parts of
> >>>>>> python-krbV were left uncovered, so it can contain some surprises.
> >>>>>>
> >>>>>> === Wild speculation follows ===
> >>>>>> 1.5 second is incredibly long time, it sounds like some kind of timeout.
> >>>>>> Krb5 libs have usual timeout = 1 second per request.
> >>>>>>
> >>>>>> Are all KDCs in /etc/krb5.conf alive and reachable?
> >>>>> In this case, as I'm referring to the extreme slowness of the Web UI,
> >>>>> the KDC is on the same system (the ipa server) that is making the
> >>>>> request, correct?
> >>>>>
> >>>>>> Is SSSD running on problematic server?
> >>>>> Yes. Again, I'm guessing the problematic server is the IPA server itself.
> >>>>>
> >>>>>> Is proper KDC selected by SSSD KDC auto-locator plugin?
> >>>>>> (See /var/lib/sss/pubconf/)
> >>>>> Yes, I checked that file and it is the IP address of the IPA server on
> >>>>> the same server. Perhaps should this be 127.0.0.1 instead?
> >>>>>
> >>>>> I also have checked the resolv.conf file, and indeed the IP points to
> >>>>> the IPA server itself (same machine) as expected. Both forward and
> >>>>> reverse DNS work. I'm not really sure what else could be setup
> >>>>> incorrectly to cause any KDC slowness.
> >>>>>
> >>>>> Due to the extreme UI slowness issue, I have not created any replicas
> >>>>> so this system is it. I'm not so sure I would be able to see the 1.5 s
> >>>>> delay if it weren't compounded by the overall slowness of the Web UI,
> >>>>> however, the KDC seems to perform well for other systems in the realm.
> >>>>> I'm certainly not taxing it with a huge load, but tickets seem to be
> >>>>> issued without delay.
> >>>> Stephen,
> >>>> another user sent me a wireshark trace for a similar performance issue.
> >>>> So far I see a pause when doing the first leg of a SASL authentication.
> >>>> This may well explain also your issue.
> >>> Hi, I experience the same delay in SASL authentication. The number I
> >>> posted on freeipa-users, show a 1-2 second delay with SASL
> >>> authentication:
> >>>
> >>> # time ldapsearch -x uid=bdteg01662 dn
> >>> # extended LDIF
> >>> #
> >>> # LDAPv3
> >>> # base<dc=xxx,dc=gob,dc=ve> (default) with scope subtree
> >>> # filter: uid=bdteg01662
> >>> # requesting: dn
> >>> #
> >>>
> >>> # bdteg01662, users, accounts, xxx.gob.ve
> >>> dn: uid=bdteg01662,cn=users,cn=accounts,dc=xxx,dc=gob,dc=ve
> >>>
> >>> # search result
> >>> search: 2
> >>> result: 0 Success
> >>>
> >>> # numResponses: 2
> >>> # numEntries: 1
> >>>
> >>> real 0m0.006s
> >>> user 0m0.001s
> >>> sys 0m0.003s
> >>>
> >>> # time ldapsearch -Y GSSAPI uid=bdteg01662 dn
> >>> SASL/GSSAPI authentication started
> >>> SASL username: admin at XXX.GOB.VE
> >>> SASL SSF: 56
> >>> SASL data security layer installed.
> >>> # extended LDIF
> >>> #
> >>> # LDAPv3
> >>> # base<dc=xxx,dc=gob,dc=ve> (default) with scope subtree
> >>> # filter: uid=bdteg01662
> >>> # requesting: dn
> >>> #
> >>>
> >>> # bdteg01662, users, accounts, xxx.gob.ve
> >>> dn: uid=bdteg01662,cn=users,cn=accounts,dc=xxx,dc=gob,dc=ve
> >>>
> >>> # search result
> >>> search: 4
> >>> result: 0 Success
> >>>
> >>> # numResponses: 2
> >>> # numEntries: 1
> >>>
> >>> real 0m2.344s
> >>> user 0m0.007s
> >>> sys 0m0.005s
> >> Can you post excerpts from your 389 access log showing the sequence of
> >> operations for this connection, bind and search?
> > Here they are:
> >
> > [01/Aug/2012:10:39:40 -041800] conn=33 fd=70 slot=70 connection from 172.18.32.246 to 172.18.32.246
> > [01/Aug/2012:10:39:40 -041800] conn=33 op=0 BIND dn="" method=sasl version=3 mech=GSSAPI
> > [01/Aug/2012:10:39:42 -041800] conn=33 op=0 RESULT err=14 tag=97 nentries=0 etime=2, SASL bind in progress
>
> Yep, this is it - this should not be taking 2 seconds. I'd like to see
> what internal operations are going on in this time. Try this - follow
> the directions at http://port389.org/wiki/FAQ#Troubleshooting but for
> the access log, to turn on Heavy trace output debugging:
>
> dn: cn=config
> changetype: modify
> replace: nsslapd-accesslog-level
> nsslapd-accesslog-level: 4
>
> Then turn the access log level back to the default (256) after
> reproducing the problem. We should then be able to see the sequence of
> internal operations triggered by the BIND dn="" method=sasl version=3
> mech=GSSAPI
>
Here they are, with the 2 second delay:
[01/Aug/2012:16:09:48 -041800] conn=Internal op=-1 SRCH base="cn=anonymous-limits,cn=etc,dc=XXXX,dc=XXXX,dc=ve" scope=0 filter="(|(objectclass=*)(objectclass=ldapsubentry))" attrs="nsLookThroughLimit nsIDListScanLimit nsPagedLookThroughLimit nsPagedIDListScanLimit nsSizeLimit nsTimeLimit nsPagedSizeLimit nsIdleTimeout"
[01/Aug/2012:16:09:48 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=1 etime=0
[01/Aug/2012:16:09:48 -041800] conn=Internal op=-1 SRCH base="cn=anonymous-limits,cn=etc,dc=XXXX,dc=XXXX,dc=ve" scope=0 filter="(|(objectclass=*)(objectclass=ldapsubentry))" attrs="nsLookThroughLimit nsIDListScanLimit nsPagedLookThroughLimit nsPagedIDListScanLimit nsSizeLimit nsTimeLimit nsPagedSizeLimit nsIdleTimeout"
[01/Aug/2012:16:09:48 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=1 etime=0
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 SRCH base="cn=config,cn=userRoot,cn=ldbm database,cn=plugins,cn=config" scope=1 filter="objectclass=vlvsearch" attrs=ALL
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=0 etime=0
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 SRCH base="cn=anonymous-limits,cn=etc,dc=XXXX,dc=XXXX,dc=ve" scope=0 filter="(|(objectclass=*)(objectclass=ldapsubentry))" attrs="nsLookThroughLimit nsIDListScanLimit nsPagedLookThroughLimit nsPagedIDListScanLimit nsSizeLimit nsTimeLimit nsPagedSizeLimit nsIdleTimeout"
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=1 etime=0
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 SRCH base="cn=config,cn=userRoot,cn=ldbm database,cn=plugins,cn=config" scope=1 filter="objectclass=vlvsearch" attrs=ALL
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=0 etime=0
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 SRCH base="cn=anonymous-limits,cn=etc,dc=XXXX,dc=XXXX,dc=ve" scope=0 filter="(|(objectclass=*)(objectclass=ldapsubentry))" attrs="nsLookThroughLimit nsIDListScanLimit nsPagedLookThroughLimit nsPagedIDListScanLimit nsSizeLimit nsTimeLimit nsPagedSizeLimit nsIdleTimeout"
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=1 etime=0
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 SRCH base="dc=XXXX,dc=XXXX,dc=ve" scope=2 filter="(krbPrincipalName=admin at XXXX.XXXX.VE)" attrs=ALL
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=1 etime=0
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 SRCH base="uid=admin,cn=users,cn=accounts,dc=XXXX,dc=XXXX,dc=ve" scope=0 filter="(|(objectclass=*)(objectclass=ldapsubentry))" attrs="nsLookThroughLimit nsIDListScanLimit nsPagedLookThroughLimit nsPagedIDListScanLimit nsSizeLimit nsTimeLimit nsPagedSizeLimit nsIdleTimeout"
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=1 etime=0
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 SRCH base="uid=admin,cn=users,cn=accounts,dc=XXXX,dc=XXXX,dc=ve" scope=0 filter="(|(objectclass=*)(objectclass=ldapsubentry))" attrs=ALL
[01/Aug/2012:16:09:50 -041800] conn=Internal op=-1 RESULT err=0 tag=48 nentries=1 etime=0
Just for kick I tried the search that appears in the log, and it returns
immediately:
ldapsearch -x -b "cn=anonymous-limits,cn=etc,dc=bt,dc=gob,dc=ve" "(|(objectclass=*)(objectclass=ldapsubentry))" nsLookThroughLimit nsIDListScanLimit nsPagedLookThroughLimit nsPagedIDListScanLimit nsSizeLimit nsTimeLimit nsPagedSizeLimit nsIdleTimeout
# extended LDIF
#
# LDAPv3
# base <cn=anonymous-limits,cn=etc,dc=bt,dc=gob,dc=ve> with scope
subtree
# filter: (|(objectclass=*)(objectclass=ldapsubentry))
# requesting: nsLookThroughLimit nsIDListScanLimit
nsPagedLookThroughLimit nsPagedIDListScanLimit nsSizeLimit nsTimeLimit
nsPagedSizeLimit nsIdleTimeout
#
# anonymous-limits, etc, bt.gob.ve
dn: cn=anonymous-limits,cn=etc,dc=bt,dc=gob,dc=ve
nsLookThroughLimit: 5000
nsSizeLimit: 5000
# search result
search: 2
result: 0 Success
# numResponses: 2
# numEntries: 1
> > [01/Aug/2012:10:39:42 -041800] conn=33 op=1 BIND dn="" method=sasl version=3 mech=GSSAPI
> > [01/Aug/2012:10:39:42 -041800] conn=33 op=1 RESULT err=14 tag=97 nentries=0 etime=0, SASL bind in progress
> > [01/Aug/2012:10:39:42 -041800] conn=33 op=2 BIND dn="" method=sasl version=3 mech=GSSAPI
> > [01/Aug/2012:10:39:42 -041800] conn=33 op=2 RESULT err=0 tag=97 nentries=0 etime=0 dn="uid=admin,cn=users,cn=accounts,dc=XXXX,dc=XXXX,dc=ve"
> > [01/Aug/2012:10:39:42 -041800] conn=33 op=3 SRCH base="dc=XXXX,dc=XXXX,dc=ve" scope=2 filter="(uid=bdteg01662)" attrs=ALL
> > [01/Aug/2012:10:39:42 -041800] conn=33 op=3 RESULT err=0 tag=101 nentries=1 etime=0
> >
> >
> >>>
> >>>
> >>>
> >>>> Can you test connecting to the ldap server using ldapsearch -Y GSSAPI
> >>>> (you need a kerberos ticket) and telling me if you experience any
> >>>> delay ?
> >>>> If you could run a bunch of searches in a loop and take a wireshark
> >>>> trace that may help analyzing the timings and seeing if there is a
> >>>> correlation.
> >>>>
> >>>> Simo.
> >>>>
> >>>
> >>> _______________________________________________
> >>> Freeipa-devel mailing list
> >>> Freeipa-devel at redhat.com
> >>> https://www.redhat.com/mailman/listinfo/freeipa-devel
--
Loris Santamaria linux user #70506 xmpp:loris at lgs.com.ve
Links Global Services, C.A. http://www.lgs.com.ve
Tel: 0286 952.06.87 Cel: 0414 095.00.10 sip:103 at lgs.com.ve
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