content/operate/rs/release-notes/legacy-release-notes/redis-pack-4-5-0-may-2017.md
If you are upgrading from a previous version, make sure to review the upgrade instructions before beginning the upgrade process.
You can upgrade to this version from any 4.4 version. If you have a version older than 4.4 you must first upgrade to 4.4 or higher, and only then upgrade to this version.
The Discovery Service provides an IP-based connection management service used when connecting to Redis Enterprise Pack databases. When used in conjunction with Redis Enterprise Pack's other high availability features, the Discovery Service assists an application cope with topology changes such as adding, removing of nodes, node failovers and so on. It does this by providing your application with the ability to easily discover which node hosts the database endpoint. The API used for discovery service is compliant with the Redis Sentinel API.
Discovery Service is an alternative for applications that do not want to depend on DNS name resolution for their connectivity. Discovery Service and DNS based connectivity are not mutually exclusive. They can be used side by side in a given cluster where some clients can use Discovery Service based connection while others can use DNS name resolution when connecting to databases.
With Redis Enterprise Pack 4.5, Auto Tiering v2 is production ready. RFv2 brings performance, reliability, and stability enhancements as well as many features customers have been waiting for.
Auto Tiering offers users of Redis Enterprise Pack and Redis Cloud Private the unique ability to operate a Redis database that spans both RAM and flash memory (SSD), but remains separate from Redis Enterprise Pack's persistence mechanisms. Whilst keys are always stored in RAM, RoF intelligently manages the location of their values (RAM vs Flash) in the database via a LRU-based (least-recently-used) mechanism. Hot values will be in RAM and infrequently used, while warm values will be ejected to flash memory. This enables you to have much larger datasets with RAM-like latency and performance, but at dramatically lower cost than an all-RAM database.
Support for additional Redis commands and features:
Support has been added RHEL 7.3 with this version.
Important fixes in RP 4.5.0-22
Important fixes in RP 4.5.0-31
Important fixes in RP 4.5.0-35
Important fixes in RP 4.5.0-43
Important fixes in RP 4.5.0-47
Important fixes in RP 4.5.0-51