Backed out changeset 74a1c5ce90d4

[m6w6/libmemcached] / docs / memcached_set.pod

diff --git a/docs/memcached_set.pod b/docs/memcached_set.pod
index 5e7ac18626e2ef8bccc660c86b2a5182bc8cdc2e..0d9a7e1f4865c40a8847dab1b3164a7ae40ad304 100755 (executable)
--- a/docs/memcached_set.pod
+++ b/docs/memcached_set.pod
@@ -143,6 +143,24 @@ objects to particular servers.
 If you are looking for performance, memcached_set() with non-blocking IO is 
 the fastest way to store data on the server.
 
+All of the above functions are supported with the C<MEMCACHED_BEHAVIOR_USE_UDP>
+behavior enabled. But when using these operations with this behavior on, there 
+are limits to the size of the payload being sent to the server.  The reason for 
+these limits is that the Memcahed Server does not allow multi-datagram requests
+and the current server implementation sets a datagram size to 1400 bytes. Due 
+to protocol overhead, the actual limit of the user supplied data is less than 
+1400 bytes and depends on the protocol in use as well as the operation being 
+executed. When running with the binary protocol, C< MEMCACHED_BEHAVIOR_BINARY_PROTOCOL>, 
+the size of the key,value, flags and expiry combined may not exceed 1368 bytes. 
+When running with the ASCII protocol, the exact limit fluctuates depending on 
+which function is being executed and whether the function is a cas operation 
+or not. For non-cas ASCII set operations, there are at least 1335 bytes available 
+to split among the key, key_prefix, and value; for cas ASCII operations there are 
+at least 1318 bytes available to split among the key, key_prefix and value. If the
+total size of the command, including overhead, exceeds 1400 bytes, a C<MEMCACHED_WRITE_FAILURE>
+will be returned.
+
+
 =head1 RETURN
 
 All methods return a value of type C<memcached_return>.