We haven't found any specific bugs with lib-ssl-iostream so far, but we did find istream-multiplex bug that could cause hangs with doveadm-doveadm connections. Could be worth testing if it helps: https://github.com/dovecot/core/commit/bbe546bc637a6ac5c9e91fc8abefce62e4950d07
> On 30. Dec 2022, at 14.37, songliny <songl...@synology.com> wrote: > > Hi All, > We are using dovecot 2.3.19.1 > We created a account with more than 1000 mail folders in Maildir format to > reproduce the issue. > After weeks of testing, we have found a logic that may cause dsync to > encounter the error - no activity for 900 seconds.... > The function, dsync_ibc_stream_input, is the callback function after some > data are ready for be read. > This is part of what it does. > o_stream_cork(ibc->output); > ibc->ibc.io_callback(ibc->ibc.io_context); > o_stream_uncork(ibc->output); > Normally, ibc->ibc.io_callback(ibc->ibc.io_context) reads some data and > then processes it. > But when dsync connects over tcps, > it uses function implementations in lib-ssl-iostream to send and receive data. > And this simplified call stack would result in some data are read when > calling o_stream_uncork > > o_stream_uncork => o_stream_flush => o_stream_ssl_flush_buffer => > openssl_iostream_bio_sync => openssl_iostream_bio_input > > If some data arrive after ibc->ibc.io_callback(ibc->ibc.io_context) and > before o_stream_uncork, > o_stream_uncork would read the data and then return. > After o_stream_uncork returns, dsync then waits for new data to be read or > written. > But because the data had been read in o_stream_uncork, and there may be no > new data to be read, > dsync may then wait until timeout is met. > It may happen, but it is hard to reproduce. > If you also encounter this situation, you may try to use dsync over tcp > connection. > It does not read data when calling o_stream_uncork. > As a result, it may not stuck. > Back to the error itself, > Maybe openssl-stream should not read data when doing uncork(flush)? > Song-Lin Yang _______________________________________________ dovecot mailing list -- dovecot@dovecot.org To unsubscribe send an email to dovecot-le...@dovecot.org
