Print

Print


Hi Chris,

OK, I'll compare thsi with what is happening with our 2 redirector case.
Could you also send log files from each redirector olbd and xrootd;
thanks. In the meantime, at least there is a work-around.

Andy


On Wed, 2 Mar 2005, Brew, CAJ (Chris) wrote:

> Hi,
>
> OK I've done a some more debugging and whilst I haven't caught the
> problem on servers that have got the debug option switch on I have got
> some more info.
>
> It's pretty definitely to do with the second load balancer. I ran all
> day today with one load balancer without running into the problems but
> about 30 mins after I restarted the second load balancer I ran into it
> again. Stopping the olbd abd xrootd on the second LB restored access to
> the files.
>
> It's possible I've got this setup misconfigured so the config file from
> the LBs is attached below.
>
> I'll continue to try to get debug output from an LB and a dataserver.
> The servers don't crash so I won't be able to get core dumps.
>
> Yours,
> Chris.
>
> [xrootd107] /opt/xrootd/etc > cat xrootd.cf
> # RAL XROOTD base config file
> # CAJB 051004
>
> # Xrd Configuration
>
> # xrootd configuration
> xrootd.fslib /opt/xrootd/lib/libXrdOfs.so
> xrootd.export /store
>
> #ODC Configuration
> odc.manager xrootd107.gridpp.rl.ac.uk 1095
> odc.manager xrootd108.gridpp.rl.ac.uk 1095
>
> # OFS Configuration
> ofs.redirect remote xrootd107.rl.ac.uk
> ofs.redirect remote xrootd108.rl.ac.uk
> ofs.redirect target csfnfs35.rl.ac.uk
> ofs.redirect target csfnfs41.rl.ac.uk
> ofs.redirect target csfnfs45.rl.ac.uk
> ofs.redirect target csfnfs46.rl.ac.uk
> ofs.redirect target csfnfs47.rl.ac.uk
> ofs.redirect target csfnfs48.rl.ac.uk
> ofs.redirect target csfnfs49.rl.ac.uk
>
> #OLB Configuration
> olb.port 1095
> olb.subscribe xrootd107.gridpp.rl.ac.uk 1095
> olb.subscribe xrootd108.gridpp.rl.ac.uk 1095
> olb.path r /store
> olb.wait
> olb.trace debug
>
> odc.trace debug
> ofs.trace debug
>
> #OSS Configuration
> oss.path /store r/o
> # Manager config for xrootd redirectors
> odc.trace redirect
> olb.allow host csfnfs*.rl.ac.uk
> olb.allow host csflnx108.rl.ac.uk
> olb.allow host xrootd107.gridpp.rl.ac.uk
> olb.allow host xrootd108.gridpp.rl.ac.uk
>
> > -----Original Message-----
> > From: Andrew Hanushevsky [mailto:[log in to unmask]]
> > Sent: 01 March 2005 19:49
> > To: Brew, CAJ (Chris)
> > Cc: Olaiya, EO (Emmanuel); [log in to unmask]
> > Subject: RE: olbd tracing
> >
> > Hi Chris,
> >
> > Yes, especially if it thinks one of the two is not
> > particularly responsive
> > to its requests. The xrootd redirectors are programmed to be greedy.
> >
> > Andy
> >
> > On Tue, 1 Mar 2005, Brew, CAJ (Chris) wrote:
> >
> > > Hi,
> > >
> > > The clients should only know about one of the load balancers but the
> > > load balancers know about each other from the olbd
> > "network" since they
> > > share a config file and log into each other. So when the
> > client asks the
> > > xrootd on the LB server for a file could it be asking the
> > olbd on the
> > > other LB server to find the file for it.
> > >
> > > That could explain why what looked to be an intermittant
> > problem on the
> > > LB server's olbd affected finding files via both LB servers
> > in the same
> > > way at the same time.
> > >
> > > Yours,
> > > Chris.
> > >
> > > > -----Original Message-----
> > > > From: Andrew Hanushevsky [mailto:[log in to unmask]]
> > > > Sent: 01 March 2005 17:40
> > > > To: Brew, CAJ (Chris)
> > > > Cc: Olaiya, EO (Emmanuel); [log in to unmask]
> > > > Subject: RE: olbd tracing
> > > >
> > > > Hi Chris,
> > > >
> > > > Yes and no. Depends on what client you use. The client
> > code has gone
> > > > through several changes. Some always ask only one
> > redirector, others
> > > > switch back and forth. But, in any case, you should have
> > > > looked at both
> > > > redirector logs. Presumably, the xrootd defaults are
> > being used (i.e.,
> > > > fail-over mode). Take a look at the xrootd logs on the
> > > > redirector to see
> > > > if anything strange is going on there.
> > > >
> > > > Andy
> > > >
> > > >
> > > > On Tue, 1 Mar 2005, Brew, CAJ (Chris) wrote:
> > > >
> > > > > Hmmm...
> > > > >
> > > > > Actually there are some debug messages in the log file now:
> > > > >
> > > > > When I just ran another test I got:
> > > > >
> > > > > 050301 16:46:39 24895 do_Select Lookup delay
> > > > xrootd107.gridpp.rl.ac.uk 5
> > > > > 050301 16:46:39 24895 Receive From csfnfs49.rl.ac.uk:1094:
> > > > 7@0 have r
> > > > > /store/test/csfnfs49.01.root
> > > > > 050301 16:46:44 24895 Receive From
> > > > xrootd107.gridpp.rl.ac.uk: 35 select
> > > > > r /store/test/csfnfs49.01.root
> > > > > 050301 16:46:44 24895 do_Select Redirect
> > > > xrootd107.gridpp.rl.ac.uk ->
> > > > > csfnfs49.rl.ac.uk:1094 for /store/test/csfnfs49.01.root
> > > > >
> > > > > Is it possible that because there was another load
> > balancer in the
> > > > > set-up it was asking that to find the files for it? That
> > > > other machine
> > > > > has now gone down to be reinstalled with SL3 and now we're
> > > > getting more
> > > > > logging info.
> > > > >
> > > > > Weird.
> > > > >
> > > > > Chris.
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: [log in to unmask]
> > > > > > [mailto:[log in to unmask]] On Behalf Of
> > > > > > Brew, CAJ (Chris)
> > > > > > Sent: 01 March 2005 16:13
> > > > > > To: Andrew Hanushevsky; Olaiya, EO (Emmanuel)
> > > > > > Cc: [log in to unmask]
> > > > > > Subject: RE: olbd tracing
> > > > > >
> > > > > > cc'd to Manny in case he doesn't catch it on the list.
> > > > > >
> > > > > > The machine I'm trying to turn the logging on on is
> > > > > > xrootd107.gridpp.rl.ac.uk our new master load balancer.
> > > > We don't have
> > > > > > root access on the box but can restart the deamons and modify
> > > > > > the config
> > > > > > file.
> > > > > >
> > > > > > I started the deamon with the -d option by running StopOLB
> > > > > > and StartOLB
> > > > > > -d rather than using the sudo /sbin/service olbd start|stop
> > > > > > we normally
> > > > > > do.
> > > > > >
> > > > > > We haven't had any problems since I reduced the number of
> > > > > > xrootd servers
> > > > > > in the cluster but I've now only got about 7TB free on the
> > > > > > servers left
> > > > > > in the cluster so will run out of room in about a week.
> > > > > >
> > > > > > Yours,
> > > > > > Chris.
> > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: Andrew Hanushevsky [mailto:[log in to unmask]]
> > > > > > > Sent: 01 March 2005 15:53
> > > > > > > To: Brew, CAJ (Chris)
> > > > > > > Cc: Andrew Hanushevsky; [log in to unmask]
> > > > > > > Subject: RE: olbd tracing
> > > > > > >
> > > > > > > Hi Chris,
> > > > > > >
> > > > > > > OK, something seems to be amiss with the overall
> > > > > > configuration if even
> > > > > > > this doesn't work. Let me get together with Manny and take a
> > > > > > > look at what
> > > > > > > is actually running and how it is put together. Manny when?
> > > > > > >
> > > > > > > Andy
> > > > > > >
> > > > > > > On Tue, 1 Mar 2005, Brew, CAJ (Chris) wrote:
> > > > > > >
> > > > > > > > Hi,
> > > > > > > >
> > > > > > > > I've got:
> > > > > > > >
> > > > > > > > olb.trace debug
> > > > > > > > odc.trace debug
> > > > > > > > ofs.trace debug
> > > > > > > >
> > > > > > > > in my xrootd.cf file and started the olbd with -d on
> > > > the LB server
> > > > > > > > [xrootd107] /opt/xrootd/etc > ps fwwwU bbdatsrv
> > > > > > > >   PID TTY      STAT   TIME COMMAND
> > > > > > > > 18801 ?        S      0:00 sshd: bbdatsrv@pts/0
> > > > > > > > 18803 pts/0    S      0:00 -bash
> > > > > > > > 25484 pts/0    R      0:00  \_ ps fwwwU bbdatsrv
> > > > > > > > 24895 pts/0    S      0:00 /opt/xrootd/bin/olbd -d -m -l
> > > > > > > > /opt/xrootd/logs/olbdlog -c /opt/xrootd//etc/xrootd.cf
> > > > > > > > 23940 pts/0    S      0:00 /opt/xrootd/bin/xrootd -r -l
> > > > > > > > /opt/xrootd/logs/xrdlog -c /opt/xrootd/etc/xrootd.cf
> > > > > > > > 23975 pts/0    S      0:00 /opt/xrootd/bin/xrootd -r -l
> > > > > > > > /opt/xrootd/logs/xrdlog -c /opt/xrootd/etc/xrootd.cf
> > > > > > > >
> > > > > > > > but am still not getting any debug info on how it's
> > > > > > > locating the files:
> > > > > > > >
> > > > > > > > the old.trace debug on the Data Servers does get me:
> > > > > > > >
> > > > > > > > 050301 11:45:08 616 Receive From
> > xrootd108.gridpp.rl.ac.uk:
> > > > > > > 7@0  state
> > > > > > > > /store...
> > > > > > > >
> > > > > > > > when looking for a file.
> > > > > > > >
> > > > > > > > Anyone know what else I need on the LB server?
> > > > > > > >
> > > > > > > > Thanks,
> > > > > > > > Chris.
> > > > > > > >
> > > > > > > > > -----Original Message-----
> > > > > > > > > From: Andrew Hanushevsky [mailto:[log in to unmask]]
> > > > > > > > > Sent: 23 February 2005 20:59
> > > > > > > > > To: Brew, CAJ (Chris)
> > > > > > > > > Cc: [log in to unmask]
> > > > > > > > > Subject: Re: olbd tracing
> > > > > > > > >
> > > > > > > > > Hi Chris,
> > > > > > > > >
> > > > > > > > > That's starting the olbd with the -d option
> > (for debugging).
> > > > > > > > >
> > > > > > > > > ----- Original Message -----
> > > > > > > > > From: "Brew, CAJ (Chris)" <[log in to unmask]>
> > > > > > > > > To: "Andrew Hanushevsky" <[log in to unmask]>
> > > > > > > > > Cc: <[log in to unmask]>
> > > > > > > > > Sent: Wednesday, February 23, 2005 11:01 AM
> > > > > > > > > Subject: RE: olbd tracing
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > > Hi Andy,
> > > > > > > > > >
> > > > > > > > > > I don't think the odc.trace redirect is the one
> > > > I'm looking
> > > > > > > > > for. What's
> > > > > > > > > > the directive that puts the "have ?" and
> > "have" replies
> > > > > > > > > into the olbd
> > > > > > > > > > log.
> > > > > > > > > >
> > > > > > > > > > Once I narrow it down to the manager not
> > asking the server
> > > > > > > > > or the server
> > > > > > > > > > not replying correctly I can turn debug on on
> > the relavant
> > > > > > > > > machine. I'm
> > > > > > > > > > reluctant to turn it on on all machines because
> > > > it's a fair
> > > > > > > > > time before
> > > > > > > > > > the problem manifests itself.
> > > > > > > > > >
> > > > > > > > > > Thanks,
> > > > > > > > > > Chris.
> > > > > > > > > >
> > > > > > > > > > > -----Original Message-----
> > > > > > > > > > > From: Andrew Hanushevsky [mailto:[log in to unmask]]
> > > > > > > > > > > Sent: 22 February 2005 21:26
> > > > > > > > > > > To: Brew, CAJ (Chris); [log in to unmask]
> > > > > > > > > > > Subject: Re: olbd tracing
> > > > > > > > > > >
> > > > > > > > > > > Hi Chris,
> > > > > > > > > > >
> > > > > > > > > > > Try:
> > > > > > > > > > >
> > > > > > > > > > > odc.trace redirect
> > > > > > > > > > >
> > > > > > > > > > > for the olb try using the '-d' option; though
> > > > you may get
> > > > > > > > > > > more information
> > > > > > > > > > > than really needed.
> > > > > > > > > > >
> > > > > > > > > > > Andy
> > > > > > > > > > >
> > > > > > > > > > > ----- Original Message -----
> > > > > > > > > > > From: "Brew, CAJ (Chris)" <[log in to unmask]>
> > > > > > > > > > > To: <[log in to unmask]>
> > > > > > > > > > > Sent: Tuesday, February 22, 2005 6:53 AM
> > > > > > > > > > > Subject: olbd tracing
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > > Hi,
> > > > > > > > > > > >
> > > > > > > > > > > > What's the trace argument to add to the
> > xrootd.cf file
> > > > > > > > > to get it to
> > > > > > > > > > > > output the queries to locate files to the logs.
> > > > > > > > > > > >
> > > > > > > > > > > > We're still having problems at RAL with
> > > > > > > files/servers not being
> > > > > > > > > > > > available via the load balancers when
> > they are if you
> > > > > > > > > contact them
> > > > > > > > > > > > directly.
> > > > > > > > > > > >
> > > > > > > > > > > > Yours,
> > > > > > > > > > > > Chris.
> > > > > > > > > > > >
> > > > > > > > > > > > --
> > > > > > > > > > > >   Chris Brew  ([log in to unmask])  +44
> > 1235 446326
> > > > > > > > > > > >   Particle Physics Department
> > > > > > > > > > > >   Rutherford Appleton Laboratory
> > > > > > > > > > > >   Chilton, Didcot. Oxfordshire.
> > > > > > > > > > > >   OX11 0QX. United Kingdom.
> > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > >
> > >
> >
>
>