(ITS#8788) slapd-pcache undef not compatible with mdb

[quanah@openldap.org]

Full_Name: Quanah Gibson-Mount
Version: 2.4.45
OS: N/A
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (47.208.148.239)


The pcache backend to slapd has the option for attr sets to note if an attribute
that being cached is not defined in the local schema by prefixing it with
"undef:", such as "undef:myattr".  While this functionality works fine when
pcache is using back-bdb or back-hdb, it does not work with back-mdb.  In the
case where back-mdb is used, an error will be logged if the hidden "pcaache"
loglevel is used, but it will still attempt to answer queries (it will return no
results, but with a success return code).


At a minimum, the documentation needs to be updated to note this feature
incompatibility.  It would be additionally useful if either slapd would refuse
to start if undef was used on top of back-mdb, or pcache would log an error that
it could not answer the result from the cache, and fall back to doing a direct
lookup.