ErrorRecovery

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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

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 -l 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 file tools and plain ls where 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