Difference between revisions of "Mserver"

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The MIDAS remote server (<span style="color:darkcyan;">''mserver''</span>) provides remote access to any MIDAS client.  
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The MIDAS remote server (<span style="color:darkcyan;">''mserver''</span>) provides [[Remote Access to a Midas experiment|remote access]] to any MIDAS client.  
  
It is needed when one or more of an experiment's MIDAS clients are running on a different host. In this case, a <span style="color:darkcyan;">''mserver''</span> client must be started on the host where the experiment resides (see [[#example|example]]).
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It is needed when one or more of an experiment's MIDAS clients are running on a different host. In this case, a <span style="color:darkcyan;">''mserver''</span> client must be started on the host where the experiment resides.
  
  
 
The <span style="color:darkcyan;">''mserver''</span> utility  usually runs in the background and doesn't need to be modified. In the case where debugging is required, the mserver can be started with the -d flag which will write an entry for each transaction to a log file /tmp/mserver.log . The log entry contains the time stamp and RPC call request.
 
The <span style="color:darkcyan;">''mserver''</span> utility  usually runs in the background and doesn't need to be modified. In the case where debugging is required, the mserver can be started with the -d flag which will write an entry for each transaction to a log file /tmp/mserver.log . The log entry contains the time stamp and RPC call request.
  
More than one copy of <span style="color:darkcyan;">''mserver''</span> can be started on a system, provided they use different tcp ports. This is useful if, for example, [[exptab|different experiments]] are in use on a single host at the same time. To start a version of <span style="color:darkcyan;">''mserver''</span> on a different port, use the -p argument, e.g.  
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More than one copy of <span style="color:darkcyan;">''mserver''</span> can be started on a system, provided they use different tcp ports. This is useful if, for example, [[exptab|different experiments]] are in use on a single host at the same time. To start a version of <span style="color:darkcyan;">''mserver''</span> on a different port, use the -p argument (see [[#Example|example]]). To restrict access to the remote host to certain nodes, use the -a argument as shown below.
  
  mserver -p XXXX -D
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=== Example ===
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  mserver -p 7072 -D
 
  mserver -p 7071 -D -a localhost -a node01 -a node02 -a node03
 
  mserver -p 7071 -D -a localhost -a node01 -a node02 -a node03
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To connect a client to this version of mserver, use the format "hostname:port", e.g.
 
To connect a client to this version of mserver, use the format "hostname:port", e.g.
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         [-m ] : Multi process server (default)
 
         [-m ] : Multi process server (default)
 
         [-p ] : Port number; listen for connections on non-default tcp port
 
         [-p ] : Port number; listen for connections on non-default tcp port
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        [-a ] : Hostname: only allow access for a specified host. Multiple -a arguments can be used (see [[#Example|example]]).
 
         [-d ] : Write debug info to /tmp/mserver.log
 
         [-d ] : Write debug info to /tmp/mserver.log
 
         [-D ] : Become a Daemon
 
         [-D ] : Become a Daemon
 
     Usage
 
     Usage
 
       >mserver -D
 
       >mserver -D
 
== Example ==
 
If an mserver client is '''not''' running on host dasdevpc2, then an attempt to run a client on dasdevpc2 from a remote computer (isdaq01) will result in an error message:
 
 
:[bnmr@isdaq01 ~/online]$ odb -e t2kgas -h dasdevpc2
 
:Cannot connect to remote host
 
 
If a mserver client is now started on host dasdevpc2,
 
 
:[suz@dasdevpc2 ~]$ mserver -D
 
:mserver started interactively
 
:Becoming a daemon...
 
 
Now one can connect to the remote experiment :
 
 
:[bnmr@isdaq01 ~/online]$ odb -e t2kgas -h dasdevpc2
 
:[dasdevpc2:t2kgas:S]/>quit
 

Revision as of 13:25, 31 July 2014

The MIDAS remote server (mserver) provides remote access to any MIDAS client.

It is needed when one or more of an experiment's MIDAS clients are running on a different host. In this case, a mserver client must be started on the host where the experiment resides.


The mserver utility usually runs in the background and doesn't need to be modified. In the case where debugging is required, the mserver can be started with the -d flag which will write an entry for each transaction to a log file /tmp/mserver.log . The log entry contains the time stamp and RPC call request.

More than one copy of mserver can be started on a system, provided they use different tcp ports. This is useful if, for example, different experiments are in use on a single host at the same time. To start a version of mserver on a different port, use the -p argument (see example). To restrict access to the remote host to certain nodes, use the -a argument as shown below.

Example

mserver -p 7072 -D
mserver -p 7071 -D -a localhost -a node01 -a node02 -a node03


To connect a client to this version of mserver, use the format "hostname:port", e.g.

# frontend started from client node
fe_test -h node01:7071 -e test
 
# frontend started from the backend node00 
ssh -n node01 /home/expt/online/fe_test.exe -h node00:7071 -e test -i 0 -D

Starting mserver

   Arguments
       [-h ] : help
       [-s ] : Single process server
       [-t ] : Multi thread server
       [-m ] : Multi process server (default)
       [-p ] : Port number; listen for connections on non-default tcp port
       [-a ] : Hostname: only allow access for a specified host. Multiple -a arguments can be used (see example).
       [-d ] : Write debug info to /tmp/mserver.log
       [-D ] : Become a Daemon
   Usage
     >mserver -D