Added Recovery Interval in Milliseconds

For very high-speed message systems, the memory used for recovery can get to
be very large. The corrent limitation on that reduction is the ZMQ_RECOVERY_IVL
of 1 sec. I added in an additional option ZMQ_RECOVERY_IVL_MSEC, which is the
Recovery Interval in milliseconds. If used, this will override the previous
one, and allow you to set a sub-second recovery interval. If not set, the
default behavior is to use ZMQ_RECOVERY_IVL.

Signed-off-by: Bob Beaty <rbeaty@peak6.com>

2 files changed, 44 insertions, 0 deletions

diff --git a/doc/zmq_getsockopt.txt b/doc/zmq_getsockopt.txt
index 7f73e1c..132e7b3 100644
--- a/doc/zmq_getsockopt.txt
+++ b/doc/zmq_getsockopt.txt
@@ -167,6 +167,26 @@ Default value:: 10
 Applicable socket types:: all, when using multicast transports
 
 
+ZMQ_RECOVERY_IVL_MSEC: Get multicast recovery interval in milliseconds
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The 'ZMQ_RECOVERY_IVL'_MSEC option shall retrieve the recovery interval, in
+milliseconds, for multicast transports using the specified 'socket'.  The
+recovery interval determines the maximum time in seconds that a receiver
+can be absent from a multicast group before unrecoverable data loss will
+occur.
+
+For backward compatibility, the default value of 'ZMQ_RECOVERY_IVL_MSEC' is
+-1 indicating that the recovery interval should be obtained from the
+'ZMQ_RECOVERY_IVL' option. However, if the 'ZMQ_RECOVERY_IVL_MSEC' value is
+not zero, then it will take precedence, and be used.
+
+[horizontal]
+Option value type:: int64_t
+Option value unit:: milliseconds
+Default value:: -1
+Applicable socket types:: all, when using multicast transports
+
+
 ZMQ_MCAST_LOOP: Control multicast loop-back
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 The 'ZMQ_MCAST_LOOP' option controls whether data sent via multicast
diff --git a/doc/zmq_setsockopt.txt b/doc/zmq_setsockopt.txt
index 86b01e4..58f04b3 100644
--- a/doc/zmq_setsockopt.txt
+++ b/doc/zmq_setsockopt.txt
@@ -171,6 +171,30 @@ Default value:: 10
 Applicable socket types:: all, when using multicast transports
 
 
+ZMQ_RECOVERY_IVL_MSEC: Set multicast recovery interval in milliseconds
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The 'ZMQ_RECOVERY_IVL_MSEC' option shall set the recovery interval, specified
+in milliseconds (ms) for multicast transports using the specified 'socket'.
+The recovery interval determines the maximum time in milliseconds that a
+receiver can be absent from a multicast group before unrecoverable data loss
+will occur.
+
+A non-zero value of the 'ZMQ_RECOVERY_IVL_MSEC' option will take precedence
+over the 'ZMQ_RECOVERY_IVL' option, but since the default for the
+'ZMQ_RECOVERY_IVL_MSEC' is -1, the default is to use the 'ZMQ_RECOVERY_IVL'
+option value.
+
+CAUTION: Exercise care when setting large recovery intervals as the data
+needed for recovery will be held in memory. For example, a 1 minute recovery
+interval at a data rate of 1Gbps requires a 7GB in-memory buffer.
+
+[horizontal]
+Option value type:: int64_t
+Option value unit:: milliseconds
+Default value:: -1
+Applicable socket types:: all, when using multicast transports
+
+
 ZMQ_MCAST_LOOP: Control multicast loop-back
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 The 'ZMQ_MCAST_LOOP' option shall control whether data sent via multicast