[stunnel-users] Redis with stunnel, need to reset a client connection if the remote server drops

Cocytus the.cocytus at gmail.com
Mon Apr 20 19:29:01 CEST 2015

Hello all, I've spent some time digging through the archives, but have yet
to turn up a solution to the issue I'm having.

We're using Redis instances on 'cloud' resources, and have successfully
gotten stunnel setup as a server on these nodes. Additionally an internal
process runs and connects to a local stunnel client that then connects to
the remote cloud instance. This is working well enough at the moment,
however there is one issue I'm bumping into.

If the remote EC2 node goes dark for a bit (ie: reboot), the local stunnel
client will reconnect, however the internal process which is establishing
its connection to the local stunnel client does not get disconnected and
therefore doesn't know that redis became unavailable and needs to
re-subscribe to the redis stream. I need to invalidate the established
session when the remote reconnects.

Can this be accomplished with either a TIMEOUT value or session statement?
Below is a sample of the configuration:

client = yes
verify = 2
CApath = /etc/ssl/certs
sslVersion = TLSv1
accept =
connect = some-ec2-node.com:6379

$ stunnel4 -version
stunnel 4.53 on x86_64-pc-linux-gnu platform
Compiled with OpenSSL 1.0.1e 11 Feb 2013
Running  with OpenSSL 1.0.1f 6 Jan 2014
Update OpenSSL shared libraries or rebuild stunnel

Global options:
debug           = daemon.notice
pid             = /var/run/stunnel4.pid
RNDbytes        = 64
RNDfile         = /dev/urandom
RNDoverwrite    = yes

Service-level options:
ciphers         = ALL:!SSLv2:!aNULL:!EXP:!LOW:-MEDIUM:RC4:+HIGH
curve           = prime256v1
session         = 300 seconds
sslVersion      = TLSv1 for client, all for server
stack           = 65536 bytes
TIMEOUTbusy     = 300 seconds
TIMEOUTclose    = 60 seconds
TIMEOUTconnect  = 10 seconds
TIMEOUTidle     = 43200 seconds
verify          = none

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.stunnel.org/pipermail/stunnel-users/attachments/20150420/eebb2692/attachment.html>

More information about the stunnel-users mailing list