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#Development
#Programmer's Guide
#User's Guide
#References

Development

Overview

Background

The MPS History (MpsHist) is a software system for storing MPS History Messages in an RDB.

Thesaurus
  • LP: link processor

Requirements

Use Cases
  1. User must figure out what's going on with MPS (performance statistics).
    • Author: snorum
    • Reason: Our mission.
  2. User must search and do analysis on messages.
    • Author: snorum
    • Reason: For diagnostics.
  3. User must be able to register MpsHist with LP.
    • Author: snorum
    • Reason: Zero configuration, dynamic change.
  4. User must switch from one MpsHist to another.
    • Author: snorum
    • Reason: Prevent loss of messages.
  5. User must be able to access all info messages.
    • Author: snorum
    • Reason: diagnostics
  6. User must be able to specify path to ConfigDB.
    • Author: snorum
    • Reason: changes in the hardware.
Functional Specification
  1. MpsHS must capture all messages.
    • Origin: Use Case #1
    • How to test: All accepted messages must be in the database.
  2. MpsHS must write all messages to RDB.
    • Origin: Use Case #2
    • How to test: All accepted messages must be in the database.
  3. MpsHs must send notification messages to LP at a rate of 0.2 Hz.
    • Origin: Use Case #3
    • How to test: Get messages from LP.
  4. One must be able to run several copies of MpsHS.
    • Origin: Use Case #4
    • How to test: Have 2 of them running.
  5. MpsHS must log all info messages.
    • Origin: Use Case #5
    • How to test: Look at the log.
  6. MpsHS must accept the path to ConfigDB as a command-line parameter.
    • Origin: Use Case #6
    • How to test: Finds ConfigDB as specified through command-line.
Constraints
  • Messages are streamed at up to 1MB/sec.
  • MpsHS must support Oracle RDB.
  • LP is a time-critical VME IOC (2.8 msecs delay accepted).
  • LP might not be sending for a while, so no timeouts must be introduced.
  • Connect only to 1 MpsHist at a time.

Design

  • Use WaitFreeWriteQueue for message repository. (needs RTJ)
  • Send a datagram to a host-name of LP on port 30000.
    • 2 byte header: protocol version 1, message type: notification 2
    • 2 bytes for port number
  • Use server port from 30001 - 30009 to receive history messages.

Comments

  • Open to the possibility of sending messages directly from LP to RDB.
  • Create a Config module

Programmer's Guide

User's Guide

Scripts

You have to run mpshist on lcls-daemon2 as laci

/etc/init.d/st.mpshist start

To stop mpshist

/etc/init.d/st.mpshist stop

Cmlog

The cmlog facility is "MPS History".

References

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