On Wed, Oct 24, 2012 at 12:50 AM, Avi Bahra <avibahra@gmail.com> wrote:
Currently I has a single threaded server based on boost ASIO. This works correctly most of the time. However on systems where i know that the disk's are slow. , the server grinds to a halt, when dealing with the blocking disk IO.
I could not find any examples or documentation in ASIO, in how to get round these issues. It appears that ASIO does not provide any support for async' disk IO.
So I assume this is handled by use of threads ? Are there any examples of using ASIO with threaded disk IO, since this must be very common use case ?
Is the strand functionality appropriate for handing disk IO, in an async' manner.
Any recommendations/advice on this issues would be greatly appreciated.
Best regards, Ta, Avi _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users
Hi Avi,
If your server performs short read/writ frequently and data to be transfer to network depend on these operations, then multi-threading does not help a lot here. I would suggest you to recheck your I/O strategies and make sure they are optimized. e.g. buffering, cache, .. etc. If they are perfect but performance still bother you, then consider to use memory mapped file or libaio.
Best, Acer.
In my case the ASIO server needs to only write to a local disk.(no reads) One write is relatively short, i.e to a log file, to record all requests, the other is to write periodically a in memory node tree. This can vary between 1-100MB. My thinking was that if I used a thread reserved for writing the node tree, it will not block the server from handling requests, on slow file systems.
I will look into memory mapped files and libaio.
Ta, Avi _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users
Log is a good candidate to be improved. You can look into asio's document. Here is an online version http://www.boost.org/doc/libs/1_51_0/doc/html/boost_asio/examples.html These documents are included in every boost distribution. The 'Services' section involves a simple logger service which can perform write operation in a background thread. Furthermore, you can also wrap your large write operation as a service to achieve shorter response time. Best, Acer.