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Experimental Physics and
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<== Date ==> <== Thread ==>

Subject: channel access client performance and gateway
From: "Rowland, J \(James\)" <james.rowland@diamond.ac.uk>
To: <tech-talk@aps.anl.gov>
Date: Wed, 8 Nov 2006 17:38:41 -0000

Hi

 

EDM panels and other CA clients in our control room have poor performance when connected to many IOCs (200+ Liberas). Using the CA proxy gateway greatly increases performance – from around 8% CPU to 0.5% CPU for a diagnostics overview panel, as show in top. The 3.14 CA client uses 2 threads per virtual circuit, is the large number of threads a problem for the scalability of channel access, or should a 2.6 Linux kernel be able to support 1000+ threads without excessive overhead in context switches and locking?

 

What have people done to improve client performance? Is the CA Proxy Gateway stable for writes (we use it extensively as a read-only gateway)?

 

Thanks


James

 

Software Engineer

Diamond Light Source

 


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