Shulou(Shulou.com)06/01 Report--

What this article shares with you is about the cluster mode of SAP Hybris and Netweaver and the problems that need to be solved in the cluster mode. The editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

Hybris supports the deployment of cluster mode, and UDP is used to communicate between different nodes through the local area network.

It is mentioned in SAP Netweaver's classic layer 3 layer that Application layer also supports multiple node:

For example, check with tcode SM53 in AG3 and find that it is composed of three node:

Cache invalidation

Both Hybris and Netweaver are faced with a problem that needs to be solved, namely cache / buffer invalidation.

# Cache Invalidation Concept in Hybris

The core of a Hybris Cluster is a network communication system that makes sure the cache of each individual cluster member only holds valid data. The nodes in the Hybris Cluster communicate using TCP (JGroups) or UDP, by sending signals to other nodes that mark some cache entries as invalid because a database item has been changed. The following is the overview of the cache invalidation process:

(1) A description of a product has changed. Therefore, all cache entries referring to the product are invalid.

(2) A cluster node where the modification has been done sends a notification to all cluster nodes that all cache entries holding the product are invalid.

(3) Nodes that hold the product in their cache discard the cached data of the product and re-retrieve the product from the database the next time the product is used.

The protocols used to notify cache invalidation between node are UDP Multicast, UDP Unicast, or JGroups. Each has its own advantages and disadvantages:

(1) JGroups provides the fastest communication and can be used both in the cloud for testing purposes and in a LAN or WAN network.

(2) UDP Multicast has some limitations in that some routers do not allow multicast network traffic by default. Amazon Elastic Compute Cloud (Amazon EC2) does not work using UDP, either.

# Cache Invalidation Concept in Netweaver

SAP help has 13 steps to explain in detail:

By default cluster mode is deactivated. See startup log:

Cloud foundry also supports distributed deployment, where nodes communicate with each other through messages. Implemented through the component NATS

It can also be observed during installation:

NATS is one of the five process that needs to be executed when CF starts:

The above are the cluster mode of SAP Hybris and Netweaver and the problems that need to be solved in the cluster mode. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.