1- FNP_IP_ENV

Set the new environment variable FNP_IP_ENV to 1 on the client. This will bypass all client-side hostname resolution during the checkout call. Improves the performance while checking out a license. When this environment variable value is set to 1, the hostname resolution function calls are bypassed and the performance is improved.

2- LM_SERVER_HIGHEST_FD (from 11.14 Lic Admin Guide)
Used to set the highest file descriptor value, which controls the maximum number of client connections to the lmgrd is <= 1024. The default value for
windows is 4096 and for non windows is 1024. See Table 24-2, Comparison table with the behavior detail on Windows and Linux, on page 266
(KB on it : https://community.revenera.com/s/FlexNet-Publisher-Knowledge-Base/LM-SERVER-HIGHEST-FD-What-is-this-and-Why-is-it-needed/ta-p/144294/jump-to/first-unread-message)

3- Set TCP_NODELAY environment variable

TCP_NODELAY
Improves license server performance when processing license requests. Set to 1 to enable performance enhancements. Use with caution: when enabled
it may cause an increase in network traffic. Set TCP_NODELAY as System variables when setting the service to start at power up using lmtools.

4 - Set MAX_CONNECTIONS (option file keyword)
This option limits the maximum number of connections with vendor daemon.

Connection limit for the vendor daemon. The range is (31 - 10,00,000). The default value is 10,00,000 (if not specified).

On non-Windows (POSIX-compliant) platforms, the vendor daemon will consider the minimum value out of the following:
        • 'getrlimit()' call will be made once at vendor daemon startup to calculate the system limit for the number of open file descriptors
        • the value set for 'MAX_CONNECTIONS'.

Once connection limit has reached, the vendor daemon disconnects further connections with error code as -237(LM_VD_MAX_CLIENTS_REACHED). Vendor daemon holds buffer of 30 connections for interaction with important utilities (for example: lmreread, lmstat), in case connection limit is reaching towards threshold.
Important • The older clients (version < 11.16.3) may receive error code as -140(LM_BADCOMMAND) while interacting with vendor daemon and MAX_CONNECTIONS limit is already reached.

In FNP_11.16.3 only, the "ls_max_connections" vendor variable was added to lsvendor.c to set the maximum connection on vendor daemon. In FNP-11.16.4, the "ls_max_connections" vendor variable is no longer available in lsvendor.c. Instead, an option file keyword "MAX_CONNECTIONS" has been introduced