Difference between revisions of "ErrorRecovery"
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===dCache hangs=== | ===dCache hangs=== | ||
| − | A simple access to [[Dcache|dCache]] ( | + | A simple access to [[Dcache|dCache]] (accessing filespecs like <code>/pnfs/mu2e</code>) can sometimes hang for a long time. This is difficult to deal with because there are legitimate reasons dCache could respond slowly. First, please read [[Dcache|dCache]] page for background information. |
| − | dCache could be operating normally yet respond slowly | + | dCache could be operating normally yet respond slowly because |
| − | * your request was excessive, such as running find or a <code>ls -l</code> on a large number (>few hundred) files. If there are 1000's of files queried, this could take minutes, and much longer for larger numbers. | + | * your request was excessive, such as running find or a <code>ls -l</code> on a large number (>few hundred) files. If there are 1000's of files queried, this could take minutes, and much longer for larger numbers of files. Use [[FileTools|file tools]] and plain <code>ls</code> where possible. |
* you, or other users, or even other experiments could be overloading dCache. This is difficult to determine, see [[Ops|operations]] page for some monitors. dCache has several choke points and not all are easily monitored. | * you, or other users, or even other experiments could be overloading dCache. This is difficult to determine, see [[Ops|operations]] page for some monitors. dCache has several choke points and not all are easily monitored. | ||
* the files you are accessing are on tape and you have to wait fro them to come off tape. The solution is the [[Prestage|prestage files]] | * the files you are accessing are on tape and you have to wait fro them to come off tape. The solution is the [[Prestage|prestage files]] | ||
Revision as of 19:11, 20 March 2018
Introduction
Some errors occur regularly, such as when authorization expires, dCache is struggling, or a procedure is repeated when it can't be repeated. Some common situations are recorded here with advice on how to handle them. Errors that can easily be googled, such as syntax errors, will not appear here.
scons
art and fcl
art exit codes
Grid Workflows
SSL negotiation
Error creating dataset definition for ... 500 SSL negotiation failed: .
Your certificate is not of the right form
dCache hangs
A simple access to dCache (accessing filespecs like /pnfs/mu2e) can sometimes hang for a long time. This is difficult to deal with because there are legitimate reasons dCache could respond slowly. First, please read dCache page for background information.
dCache could be operating normally yet respond slowly because
- your request was excessive, such as running find or a
ls -lon a large number (>few hundred) files. If there are 1000's of files queried, this could take minutes, and much longer for larger numbers of files. Use file tools and plainlswhere possible. - you, or other users, or even other experiments could be overloading dCache. This is difficult to determine, see operations page for some monitors. dCache has several choke points and not all are easily monitored.
- the files you are accessing are on tape and you have to wait fro them to come off tape. The solution is the prestage files