Seems to always be zero, Matt, as it should be. This gives some idea of what is going on: Breakpoint 4, dcb_basic_read_SSL (dcb=0x7fffdc0158d0, nsingleread=0x7fffffff86fc) at /root/MaxScale/server/core/dcb.c:12181218 switch (SSL_get_error(dcb->ssl, *nsingleread))$352 = 16384Breakpoint 5, dcb_basic_read_SSL (dcb=0x7fffdc0158d0, nsingleread=0x7fffffff86fc) at /root/MaxScale/server/core/dcb.c:12221222 MXS_DEBUG("%lu [%s] Read %d bytes from dcb %p in state %s "Fri May 27 16:47:12 BST 2016$353 = "Successful SSL read"Breakpoint 1, dcb_read_SSL (dcb=0x7fffdc0158d0, head=0x7fffffff87d0) at /root/MaxScale/server/core/dcb.c:11911191 ss_dassert(gwbuf_length(*head) == (start_length + nreadtotal));$354 = 0Breakpoint 9, dcb_write (dcb=0x678ef0, queue=0x67d300) at /root/MaxScale/server/core/dcb.c:13701370 below_water = (dcb->high_water && dcb->writeqlen < dcb->high_water);Fri May 27 16:47:12 BST 2016$355 = 16384$356 = "Writing to the client" Breakpoint 4 shows the number of bytes read.Breakpoint 5 shows the case for analysis of the return code from the read.Breakpoint 1 shows the value of s->s3->rbuf.leftBreakpoint 9 shows the number of bytes being passed to the write function. -- View this message in context: http://openssl.6102.n7.nabble.com/OpenSSL-non-blocking-epoll-hanging-on-data-receiving-tp66355p66394.html Sent from the OpenSSL - User mailing list archive at Nabble.com. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mta.openssl.org/pipermail/openssl-users/attachments/20160527/38bf0a63/attachment.html>