Why is there a primary and secondary directory in 2-tier MFE topology

Question

Why is there a primary and secondary directory under /primo_indexes in 2-tier MFE topology

Answer

In 2-tier MFE topology there are 4 active search engines, the flow of the indexing /search process is as follows:
a. FE1 - includes: primary FE + Primary SE
b. FE2 - includes: Secondary FE + Secondary SE
c. BE slot 1: BO + Primary Agent
d. BE slot 2: Secondary Agent

Each FE uses its own SE as a slice for searches.
During Indexing:
* Primary FE calls the Primary agent to index, the index files are created in /primo_indexes Primary directory.
* Before index is complete the files are copied to the /primo_indexes Secondary directory.
During Hotswap:
* Primary FE calls the Primary agent to hotswap - the index is copied from the BO Primary directory to the Primary FE index folder,
* Primary Agent initiates the Secondary Agent to hotswap - the index is copied from the slot 2 directory to the Secondary FE index folder,

• Article last edited: 10/8/2013