Recently I came across an issue with the Search Service after a topology change.

Scenario:

You have SharePoint 2013 RTM with Search Service application Service installed and configured on a multi server farm.
You then decided to add a new server to the farm and moving over the search components to the new added one by following the given TechNet article.

So far, everything is fine and you want now remove the "old" server from farm.

ISSUE:

After changing the search topology and removing the old server from farm, you suddenly find in central admin/search admin page this Error presented:

" ​Unable to retrieve topology component health states. This may be because the admin component is not up and running."

CAUSE:

Details:
The NodeController continually fails; all topology changes fail preventing the removal of invalid components, and the Search Admin’s net.tcp management endpoint (such as net.tcp://serverName/B2C874/AdminComponent1/Management) becomes inaccessible.

Upgrade an RTM farm to the March ’13 PU without respecting this Blog Post may also put the SSA into a similar unrecoverable state. Further, the behavior also occurs if there is only a single Search Admin component in the Search Topology and this server is removed/re-joined to the farm.

   Ee721049.note(en-us,office.14).gif This is a known problem and will be fixed with Build version 15.0.4495.1000 which should be included in the April 2013 CU packages

NOTE!
To apply the April 2013 CU you must have installed the March 2013 PU's prior as mandatory for all following update packages!

Please see here for more:
For March PU install:   http://blogs.technet.com/b/steve_chen/archive/2013/03/22/3560441.aspx
for April CU install:  http://blogs.technet.com/b/steve_chen/archive/2013/04/29/3569593.aspx

 

Resolution/FIX:

Currently the only way is to recreate entirely the search service application and components to resolve this issue when your server is on RTM version.
Even installing the March and April 2013 updates may not retroactively solve the problem and you might be likely forced to recreate the search service anyway.

 

More information:
Additionally, you must consider further important steps and preparations on servers with search components installed on it before you install the mandatory march packages!

Please see here for important info: 
How to install update packages on a SharePoint farm where search component and high availability search topologies are enabled

 

Related posts:

SharePoint 2013 Build Numbers and CU's
SharePoint 2013 RTM Setup and Install
Search Service Application Issue with SharePoint 2013 preview build