LHC@home

The error message
Warning: mysql_pconnect(): Too many connections in /shift/lxfsrk4101/data01/projects/lhcathome/html/inc/db.inc on line 16
Unable to connect to database - please try again later Error: 1040Too many connections

So what is the magical number???

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The number is slightly larger than 134.

(134 is the last number i saw before I got this error)

Usually, the 'concurrent connections' is between 20 and 30.

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I'm not the LHC Alex. Just a number cruncher like everyone else here.

>>So what is the magical number???

The database connection limit is the number of connections to the database, and is set by the server administrator. A database connection is transient - just long enough to service a query, and then it's dropped. Early in the project there were attempts to tune this for best performance. Too low and the database server can't meet the normal demand for connections. Too high, and the server is run ragged by numerous different requests and response times increase substantially. Values between 50 and 400 were tried. On the old server I think it finally got set to 100. The new hardware is presumably faster, so can handle a larger limit.

It's not a value of any great importance to the community - there's nothing we can do to change it. If the limit is exceeded then we see odd messages, but the BOINC client handles it and tries again later.

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Gaspode the UnDressed
http://www.littlevale.co.uk

During night in Europe the server goes trough set of backup, cleaning and optimizing tasks which may temporarily slow down the server such that overload happens. I hope we can get this smoothier but it might not be easy.

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Markku Degerholm
LHC@home admin