MLS Server functionality

[vispr]

Hi,

 

We have 7 spectrum landscapes configured in fault tolerant i.e.., in total 14 spectro-servers in 4 different data centers.

 

We are asked for a demo to state how to create a new MLS server and make application functional during both MLS server are down.

We manually made down both MLS servers by stopping spectroserver and processd processes. We made sure like no process related to spectrum is running. Post MLS spectroserver down, we made one of our landscape completely down along with its fault tolerant spectroserver.

When we try to start one of the spectro-server during the absence both MLS servers, I have noticed that the spectroserver successfully started and established contact with the fault tolarant spectoserver. I wonder how this happened.

As per my knowledge, during spectoserver starting, it establishes a connection with either of MLS servers to get architecture and if MLS servers are not available then spectoserver fails to start. Can someone give explanation how my spectroserver successfully started in absense of MLS servers.

 

 

Regards,

Vishnu Prasad

[Jason Meader]

Hi Vishnu,

                The distributed SpectroSERVER doesn’t depend on the MLS to be up in order to start.  You can still start it.  You just don’t have the correct functionality for a distributed environment if both MLS are down.

Cheers

Jay

[ackjo04]

The job of the Main Location Server (MLS) is to propagate service advertisements among the Location Servers (LS) and communicates service locations among the LS in the Distributed SpectroSERVER (DSS) environment.

 

The LS is also used to maintain the SpectroSERVER Landscape Map and provide connection services to client application. 

 

When the Location Server process starts, it communicates with the MLS about the services it has to offer and updates the cache on the MLS. The MLS will then advertise this to the other LS in the DSS so they can update their LS cache.

The $SPECROOT/SS-Tools/HostUpdate -v command lists the LS cache for that particular system.

 

If the MLS and backup MLS should both fail, the LS on each system still has the cached information to refer to. While the MLS and backup MLS are down, if a new LS is brought up or an LS in the existing DSS should fail or restart, they will not be able to communicate with the configured MLS or backup MLS so they will only know about themselves until they regain communication with the MLS or backup MLS.

 

Reference Setting Up a Distributed SpectroSERVER Environment - CA Spectrum - 10.2 to 10.2.3 - CA Technologies Documentation