Introduction to LHC in Citrix 7.12 onwards

Hi Everyone, It's been long time I was not writing anything on the blog but I found something new and interesting so thought to share that with you.

Let's start hear lot of noise from the 7.12 that we are starting with new concept LOCAL LHC. Actually it's not new but yes there are some value addition to this. Local LHC support our end users connections incase our database get unresponsive. Prior to 7.X we were having LHC in place which was capable to handle the end users who login or used citrix environment in last ninety days.

From 7.X they changed it to Connection Leasing which is capable to serve only those end user connections which used infrastructure in past 2 weeks when database connection goes unresponsive or we can say down. One thing I missed here that during unavailability of database there would not be any modification is possible to static datastore or database.

With this new feature Citrix introduced two new services as well which will appear on all the controllers,

1.Configuration Sync Service: This service does the copy using broker service from central database and saved it in the HA service instance.

2.HA Service: Keeps the copy of database in form of LHC.

Now one question may arise how overall process would function incase outage triggers So let me explain in case there is an outage triggers from database side then Broker service instruct HA service to take the owner ship and while taking the ownership again there an election process triggers because only one controller may take the responsibility of HA service at a time, Which would accept the registration of all VDI's.

Below is the workflow for LHC: