Channel Finder operational experience at BNL work by: Gabriele Carcassi, Robert Petkus, Guobao Shen, Kunal Shroff, Lingyun Yang, written by: Gabriele Carcassi performed by: Kunal Shroff

ChannelFinder at BNL IOCs Glassfish Web service /cf-update Web proxy CSS Scripts to - populate properties - create lattice channelfinder.nsls2.bnl.gov NFS update daemon dependency data flow

Getting channels from the IOCs IOCs /cf-update channelfinder.nsls2.bnl.gov NFS dependency data flow

Getting channels from the IOCs channelfinder.nsls2.bnl.gov exports the directory /cf-update through NFS Each IOC directly or indirectly has access to it When the IOC boots, the startup script saves the output of a dbl command to a file Filename format: hostname.iocname.dbl

Updating channel list Glassfish Web service /cf-update channelfinder.nsls2.bnl.gov update daemon dependency data flow

Updating channel list Daemon monitors for changes in the /cf- update directory and updates channelfinder – Setup a script in /etc/init.d – Uses /usr/bin/inoticoming to monitor for changes in the directory – Uses CFUpdateIOC.py script coming with channel finder python client to perform the update – Ignores all the channels that ends in “_” (NSLS-II convention for “internal” channels)

Updating channel list Update process feels very fast System has been very reliable – no problems so far

Glassfish setup Glassfish Web service channelfinder.nsls2.bnl.gov dependency data flow

Glassfish setup Running Glassfish 3.1 Single instance of Glassfish for multiple applications – Will be the same deployment server for our log service (collaboration with MSU) – Each application available as an alias – Top application changes according to the alias – ChannelFinder – log

Glassfish setup Glassfish runs as glassfish user Glassfish redirects to PAM for authentication – This is supported only as root user – We had to make glassfish member of the shadow group and allow it to access /etc/shadow (for local accounts) and /etc/pam_ldap.conf (for ldap accounts) – Runs fine now

Glassfish setup In ldap created the following groups: – cf-admins, admins – cf-channels, users that adds/removes channels, currently only cf-update – cf-properties, users that can add properties, a couple of people in our group and physics group – cf-tags, users that can only add tags, more people in the physics group – aphla, accelerator physics high level application, to group tags/properties from that group

Glassfish setup Main problems – Increase max file descriptors – OutOfMemory error Used to hit it, now we don’t anymore Quantum-bug: stopped appearing once we setup the infrastructure to debug it when it would happen again

Usage from high level physics Glassfish Web service Scripts to - populate properties - create lattice channelfinder.nsls2.bnl.gov dependency data flow

Usage from high level physics Our physics group adds properties/tags From Linyun Yang (accelerator physics) talk: – From Channel Access to Channel Finder Service: Channel Accesses in Python and Matlab are simple to use. High level applications (HLA) deals with thousands of magnets, instruments and more channels. Organized/structured channel information is necessary. Channels linked to accelerator lattice and diagnostics are even better. Searching instead of remembering is easier for HLA users. – A “dictionary” service can help HLA to manage the channels and build a lattice structure to which the AP is familiar. (they done simulation, analysis with it in the design).

device FM1G4C02A Channel Name SR:C02-MG:G04A{HFCor:FM1}SR:C02-MG:G04A{VFCor:FM1} Fld-IFld-SPFld-IFld-SP handle READBACKSETPOINTREADBACKSETPOINT elemName FXM1G4C02AFYM1G4C02A elemType HFCORVFCOR elemField xy devName FM1G4C02A sEnd cell C02 girder G4 symmetry A length ordinal tags egeteputegeteput xy sys.SR

Usage from high level physics Physics group can re-create the lattice from the information in channel finder By tags, different lattices can be built, and elements can be shared between them. – Sharing is important for injection, where LTD1 and LTD2 shares a lot of elements with LTB

CSS & ChannelFinder Glassfish Web service CSS channelfinder.nsls2.bnl.gov dependency data flow

CSS & ChannelFinder See next talk!