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windowserlanglatencythriftthroughput

Multi-threaded Windows Service - Erlang

I am going to tell the problem that I have to solve and I need some suggestions if i am in the right path.

The problem is:

I need to create a Windows Service application that receive a request and do some action. (Socket communication) This action is to execute a script (maybe in lua or perl).This script models te bussiness rules of the client, querying in Databases, making request in websites and then send a response to the client.

There are 3 mandatory requirements:

  1. The service will receive a lot of request at the same time. So I think to use the worker's thread model.
  2. The service must have a high throughput. I will have many of requests at the same second.
  3. Low Latency: I must response these requests very quickly.

Every request will generate a log entries. I cant write these log entries in the physical disk at same time the scripts execute because the big I/O time. Probably I will make a queue in memory and others threds will consume this queue and write on disk.

In the future, is possible that two woker's thread have to change messages.

I have to make a protocol to this service. I was thinking to use Thrift, but i don't know the overhead involved. Maybe i will make my own protocol.

To write the windows service, i was thinking in Erlang. Is it a good idea?

Does anyone have suggestions/hints to solve this problem? Which is the better language to write this service?

Solution

  • Yes, Erlang is a good choice if you're know it or ready to learn. With Erlang you don't need any worker thread, just implement your server in Erlang style and you'll receive multithreaded solution automatically.

    Not sure how to convert Erlang program to Windows service, but probably it's doable.

    Writing to the same log file from many threads are suboptimal because requires locking. It's better to have a log-entries queue (lock-free?) and a separate thread (Erlang process?) that writes them to the file. BTW, are you sure that executing external script in another language is much faster than writing a log-record to the file?

    It's doubtfully you'll receive much better performance with your own serialization library than Thrift provides for free. Another option is Google Protocol Buffers, somebody claimed that it's faster.

    Theoretically (!) it's possible that Erlang solution won't provide you required performance. In this case consider a compilable language, e.g. C++ and asynchronous networking, e.g. Boost.Asio. But be ready that it's much more complicated than Erlang way.