* Konrad Zemek [2015-08-16 15:57+0200]

Hi all,

I've built a few different Asio-based SSL servers in my career, but in my recent project the performance and resource-efficiency was paramount (as it's a library project), so I benchmarked it to make sure.

Long story short, when benchmarking I found out that OpenSSL's error handling is a *very* serious bottleneck when scaling Asio+SSL over multiple threads. This can be "fixed", e.g. by using BoringSSL instead of OpenSSL, as BoringSSL uses thread-local storage for error data instead of locking a global mutex.

As I didn't find any resources discussing bad Asio+SSL multithreaded performance (aside of one or two messages somewhere on this mailing list that complained about the problem; unfortunately I can't seem to find them right now), I've written up my knowledge into a blog post [1]. I believe it might be very useful to anyone who wants to build a multi-threaded SSL server/client on top of Asio.

The 0.11-devel brance of has support for SSL. Any idea how that stacks up?

Konrad

[1] https://konradzemek.com/2015/08/16/asio-ssl-and-scalability/ _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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