Why is an ENQ with Qname LSERVDSN issued by Endevor?

Products

• Endevor
• Common Components and Services for z/OS

Issue/Introduction

Why is an ENQ with Qname LSERVDSN issued by Endevor to access inventory files, even L-Serv is not in use?

Environment

All Supported Releases

Resolution

An ENQ with Qname LSERVDSN is always issued by Endevor to access its inventory files. It allows the system check how the file should be opened and makes sure that LSERV will not be able to grab it, once Endevor opens it for non-LSERV access.

This QNAME will primarily be issued by L-Serv code to assume Exclusive control over a Dataset.
It will make sure that any L-Serv instance can't take control (by command ADDFILE) of these datasets and it signals to LServ's ´clients´ (e.g. Endevor) that L-Serv controls the dataset. Endevor, before it opens a dataset, will check whether it is under LSERV control, via an ENQ Test with Qname LSERVDSN and as Rname the dataset name.

If it is NOT under LSERV control, Endevor will next issue a Shared ENQ SCOPE=SYSTEMS, with Qname LSERVDSN, as Rname the dataset name and this will persist until Endevor closes the dataset.

Thus it makes sure that L-SERV can't take Exclusive control over the dataset.
This is relevant in a configuration where both L-Serv and RLS are potentially used.

Additional Information

For further detail, see the LSERVDSN ENQ fully documented in the Common Services Administrator Guide