Thanks, but I'm still confused why the server can't accept the connection when the TCP 3-way handshake is completed.
On Thursday, July 20, 2017 at 4:12:31 PM UTC+8, Norman Maurer wrote: > > Hey, > > comments inside… > > On 20. Jul 2017, at 08:50, Ronggen Liu <[email protected] <javascript:>> > wrote: > > Hello, > > *problem*: > some connections were lost when there are too many clients were trying to > connect to the server during a short time, for example, send out about 10k > connections during about 3 seconds. > > *findings:* > as i know, all the connections would be accepted in method doReadMessage of > NioServerSocketChannel, and, in fact, we did find out that some > connections were not accepted from there, but, actually, the TCP have been > created successfully with completed 3-ways handsharke. > meanwhile, we found, to some degree, we can avoid this issue by increasing > the option SO_BACKLOG of ChannelOption, currently, we set it with 8, > should be a little bit low. > > > 8 is most likely a way too low. I would not touch this setting at all if > you not want to increase it to a high-number. > > > > *questions:* > how to handle this issue? as i know, the client should receive connection > refused error when the number of the connections exceed the SO_BACKLOG, but > the client didn't receive it. > > > No it will not receive a connect refused error but the connection will > just timeout. You should check if you block the EventLoop somehow and so > not be able to accept fast enough. > > > > Thanks, > Gary > > -- > You received this message because you are subscribed to the Google Groups > "Netty discussions" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/netty/3f5aae56-1fd6-4e0b-8a6e-cfed66653c1e%40googlegroups.com > > <https://groups.google.com/d/msgid/netty/3f5aae56-1fd6-4e0b-8a6e-cfed66653c1e%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "Netty discussions" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/netty/bbccbf19-aa67-4346-83dd-566257893296%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
