Media Recorder load-balancing and failover
Unified Recorder service has two logical roles which can be colocated on the same server or distributed across multiple servers.
These roles are in nutshell:
- Recording Director: integration point with telephony vendors, provides a unified layer/acts as a mediator for media establishment, CDR events to Media Recorder role
- Media Recorder: controlled by Recording Director it records media and stores CDR information in the database
If Recording Director and Media Recorders are separated on multiple servers and there are at least one Recording Director and two Media recorders, the Recording Director can:
- Distribute the media recording tasks between Media Recorders to provide load-balancing between them. Load-balancing takes into account recorder load feedbacks (CPU, number of concurrent recording, available disk space etc...). Due to the characteristics of Unigy's recording interface, load-balancing for Unigy unlike in case of other vendors does not happen at call level rather at turret level, i.e. since there are persistent recording channels established, the Media Recorder for a turret is selected at agent login time
- If a failed/offline recorder is detected then all the calls recorded on it can failover to other Media Recorders and recording continues from the failure point.
In this setup two recorders receive the same CTI events and media streams, ie. each call is recorded twice, once by each of the two recorders.
One recorder must be marked as secondary due to:
- it should establish the duplicated mixes/media channels in the recording profile
- should mark the CDRs as a secondary record, so the UI/search can filter out the "duplications". There is an option to show secondary records too if something is missing
This setup can scale by separating Recording Director and Media Recorder role and adding the required number of Media Recorders. In each primary - secondary group there can be a single Recording Director and multiple Media Recorders. Secondary Media Recorders cannot be used by primary Recording director and vice versa
CTI/Recording Director failover
In this setup, there are two Recording Directors, one considered as active CTI service the other one as passive. To scale the deployment Media Recorders can be added.
The passive must be configured with a monitoring port pointing to the active. The passive service continuously monitors the availability of the active.
As soon as it fails, it takes over the CTI control until the active becomes available again.
This setup is only recommended if 2N recording is not desired but resiliency is a concern.