We start with reminding the relevant terminology used in the PROOF context:
- TProof
- Client
- Master
- Worker (or Slave)
- PROOF session
- Query
- Selector
- Dataset
- Package / PAR file
- PROOF-Lite
The interface class to a PROOF session. It is a sort of PROOF shell allowing high- and low-level interaction with the system. In contains a few static methods, namely TProof::Open to start a session. See reference documentation for TProof.
ROOT session run by the end-user of PROOF on her/his laptop or desktop; from this ROOT session the PROOF session is started by creating an instance of TProof with TProof::Open("master_url").
PROOF node running a ROOT application in charge of coordinating the work between workers and of merging the results. The network hostname of this machine is the string to be passed to TProof::Open to start a session. The client must therefore know the hostname of the master machine (and also the network port where the master listens, if the latter is different from the default 1093).
PROOF node running a ROOT application doing the actual work. These nodes are known by the master. The client may ignore their hostnames.
The set composed by {client, master, workers} started by a call to TProof::Open .
Process request submitted by the client to the master. Consists by a selector and a dataset.
A class deriving from TSelector providing the code to be executed.
List of files containing the TTree to be processed. It can be in the form of TChain, TFileCollection or TDSet. It can also just be a name of a TFileCollection previously registered on the master node.
Additional code needed by the selector - not available on the PROOF cluster - loaded as a separate library. The code is distributed as a PAR file (Proof ARchive), a gzipped tar-ball containing all what needed to enable the package.
Special version of PROOF designed for multi-core machines. It collapses the client and the master into the client and does not need any daemon to startup. PROOF-Lite is started passing "" or "lite://" to TProof::Open.