(ITS#4715) Proxy cache TTL does not seem to be working as documented

[ashish@ratboy.net]

Full_Name: Ashish Gawarikar
Version: 2.3.27
OS: Linux - 2.6 based
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (63.211.143.38)


Openldap 2.3.27 configured as proxy cache is behaving erratically.

Entries being answered from the proxy cache sometimes result with a negative
result, even though the LDAP server has the information.

It appears like the proxycache "forgets" that it has gotten the answer, but
doesn't re-query the target server to fetch the information again.

Proxy cache returns 'no such object' for a previously found entry if the ttl
has passed between queries:

conn=0 op=2 SRCH base="dc=mail,dc=example,dc=com" scope=2 deref=0
filter="(mailLocalAddress=account1@example.com)"
conn=0 op=2 SRCH attr=maillocaladdress
request done: ld 0x83dd3b8 msgid 3
conn=0 op=2 SEARCH RESULT tag=101 err=0 nentries=1 text=Search operation
succeeded

<-- wait "some" time here --> 

conn=0 op=3 SRCH base="dc=mail,dc=example,dc=com" scope=2 deref=0
filter="(mailLocalAddress=account1@example.com)"
conn=0 op=3 SRCH attr=maillocaladdress
conn=0 op=3 ldap_back_retry: retrying URI="ldap://ldap.example.com:389";
DN="cn=admin,dc=example,dc=com"
request done: ld 0x83dd3b8 msgid 1
request done: ld 0x83dd3b8 msgid 2
conn=0 op=3 SEARCH RESULT tag=101 err=32 nentries=0 text=No such object:
dc=mail,dc=example,dc=com