There are no specifications for protocol-level locking in either the X.500 standard nor the LDAP standard. Directories are not RDBMSs.

Your use case makes no sense. Once you've read the entry, you can do whatever calculations you want with that entry's data. Why does the entry in the directory need to be locked?

==>There are ways for applications to perform cooperative locking in LDAP, but so far it's not clear why you need it.

Actually i am using a DN

dn: guid=userId,dc=example,dc=in userId: 5000

It is having a single attribute userId. And i want to use this attribute for other entries of User for an Example:

dn: userName=rkyadav,dc=example,dc=in userName: rkyadav userId: 5000

when a request for adding a information of any user comes that time i read the value of userId and update this value by One means now it is having value of userId

dn: guid=userId,dc=example,dc=in userId: 5001

But between the process of reading and updating if some other request also reads the value of userId: 5000 then both users have the same value. But we don't want this.

so is there any mechanism through which we can hold the request,so it dose not get the value of userId between the process of reading and updating.

You told me in your reply: "There are ways for applications to perform cooperative locking in LDAP"

Please tell me about locking.