Minutes SLAC-ALTAS TDAQ Meeting 07-Sep-2006
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Present: Sarah (phone), Steffen, Amedeo, Su Dong, Rainer


Sarah:

Software week at CERN next week.  Thinking of saying something about
dbproxy in the database session.  Tuesday morning, next week.  Su
Dong: There is always the possibility for dbproxy to be useful in the
offline world as well, so there may even be an interest beyond the
online.

Met with Haimo regarding test.  He uses 1 L2 processing unit and 8
EFs.  Haimo is trying to get the process manager to work.  Have
dbproxy in the partition. There is an error related to a table version
that trying to figure out together.  Using TDAQ 1.4.1, and the ERS
version.  Will use the function to dump the queries in order to debug.

MST: A bit of panic setting HLT up on the Grid machines in Manchester.
Will learn how to set up a MySQL server there and make replicas of the
db.

LST: Debate on resources and when and how it will happen.  Mostly
questional is the timescale of November.  Will have a 'showdown'
meeting at the TDAQ week.

Location of the proxy is between HLT and DAQ.  Short discussion about
this.  Prefer the more common area DAQ.

Also: 12.0.3 delay for a week.


Amedeo:

Need to find out how to replicate the database. (Or use ssh tunnel.)
[Discussion with Sarah on db error messages found in Haimo's tests].
Error message appears to be 'no database selected'.  Suggesting to
dump() the entire request and result set, rather than just the
queries.  Four functions in the connector (2 reads and 2 writes).
This is where one needs to add the dump.  Suggest to wrap this into an
#ifdef and enable the #ifdef to get the debug output. Sarah will send
the output of the dump to Amedeo.


Steffen:

Farm set up!   30 machines in IR2. 100GBit ethernet.  Amedeo, Rainer
also have sudo.   atl-tdaq01...30.

HP Switch: hardware look very neat, software, compared to Cisco,
rather cheap.  VLAN is fairly limited, routing is extremely limited.
Multicast features.  Either flood (used as broadcast), or uses IGMP
version 2.  Annoying feature: command line interface is 'sort of'
Cisco compatible.

Plan to add the 70GB of disk space soon.  Thinks may be ready to move,
in (realistically) a 2-3 day down time.

Set up a MySQL server on tdaq01, which already has the 70GB disk.


A.O.B

Thinking about what the present at the TDAQ week.  Have a Hans/SLAC
plenary session on database.  Hans expects us to cover our half there.
Question on what kind of tests could be done at SLAC until then.
Basically the list is: start n clients at the same time, measure GBit,
how much we need to slow down multicast in order not to drop datagrams
that are bigger than 1MB.  Need to throttle the data on the sending
side.