V11.5 Update Guide

Communications Layer

In This Section Shared Memory Protocol Change Server broadcast feature enabled on all platforms

Shared Memory Protocol Change

A change has been made in V11.5 and newer to the c-treeACE shared memory client-side code to return the c-treeACE sysiocod value if the shared memory connection fails due to incompatibility. In this case, a message similar to the following will be written to the log:

The client's shared memory version (3) is not compatible with the server's shared memory version (4)

The values shown in parentheses indicate the shared memory protocol versions. The message above means that the client is using version 3 of the client protocol and the server requires version 4.

The following messages may appear as warning symptoms:

Mon Jul 2 10:51:05 2018

- User# 00001 FSHAREMM: Protocol version: server=3 client=4

Mon Jul 2 10:51:29 2018

- User# 00020 FSHAREMM: The client's shared memory version (3) is not compatible with the server's shared memory version (4)

Note: SQL communication is NOT included in this change.

Two situations may be encountered that will not fall back to TCP/IP:

1. On Windows, it is possible for a shared memory connection attempt to return error SHMP_ERR (978) due to insufficient permission.
2. On Unix (and some very old Windows clients), it is possible for a shared memory connection attempt to return error SHMC_ERR (841) due to client/server using incompatible shared memory protocol versions.

Both of the above situations are different from the standard error 133 ("server not listening"), which would be retried using TCP/IP.

Compatibility Note: This change is considered a compatibility change as the shared memory communication protocol may not automatically fail over to TCP/IP support if the cause of the shared memory connection failure is permission related.