Hello,

I have a question concerning shared memory (in linux-environment). In our company we currently have an application that is restarted once in a while. There are multiple instances running of this application (on different physical machines), and all access the same centralized database. Because of IO and Network bottleneck the start gets very slow, and takes about 10 Minutes. Besides some new data, most of the data stays the same, so reading from the database again is quite redundant. An idea is to write all relevant object to a shared memory segment, when the application is shut down. A second dummy process attaches to the same shared memory (just so that some process is still attached). If the application is restarted, it is attached again to its shared memory, and reads it to its own adress range again. There might occur a difference regarding the data so it might me necessary to load some new data afterwards, but that is different problem.

The current idea is to serialize all Objects (could be about 1-2 Gigabyte) with Apache Thrift, and write them into shared memory. With Thrift the data is more or less ordered, so creating the objects anew is possibly easier (not sure here).

My Question is:
- Does it even make sense to consider shared memory in this scenario. I've read a lot stuff about in the last few days, and for now I don't see big disadvantages (except if the application crashes, in this case I've to read from database again). On the other hand I don't know how to really implement this functionality (as I'm no experienced Developer)
- Should I aim for Boost::Interproces, considering even memory mappable files, or stay with the traditional shmat (and stuff..)?
- I guess 1-2 Gigabyte shared memory will be necessary. This amount is only needed in the gap between application shutdown and restart. Will the sheer amount of needed shared memory be a problem (all examples I found just used a few Bytes or Kilobytes)
- Does it make sense to use Thrift in this scenario?

If I am missing any information, please inform me.

Thanks in advance

Michael