Chronicle Queue Glossary

A

  • Appender: An appender is the message source. You add data by appending it to the Chronicle Queue. Sequential writes can be performed by appending to the end of queue only. There is no way to insert, or delete excerpts.

E

  • Exerpt: Excerpt is the main data container in a Chronicle Queue. In other words, each Chronicle Queue is composed of excerpts. Writing message to a Chronicle Queue means starting a new excerpt, writing message into it, and finishing the excerpt at the end.

M

  • Marshallable: TBW

R

  • Roll cycle: TBW

  • Rolling: Chronicle refers to writing to a new Chronicle Queue .cq4 file as Queue Rolling.

T

  • Tailer: A tailer is an excerpt reader optimized for sequential reads. It can perform sequential and random reads, both forwards and backwards. Tailers read the next available message each time they are called.

  • Topic: A topic is a directory of queue files. If you have a topic called mytopic, the layout could look like this:

- mytopic/
    - 20160710.cq4
    - 20160711.cq4
    - 20160712.cq4
    - 20160713.cq4