Here are my notes from some internal design work on PD2.0, the primary goals are:
- Simplify configuration, this will likely involved a custom Spring namespace handler to provide a more complete XML configuration language.
- Improve lookup speed, adding in an ExecutorService to allow for parallel lookup of attributes from various sources.
- Simplify the API, provide a try criteria API for complex searches in addition to the ability to lookup attributes for a single user.
Secondary goals:
- Add JMX monitoring of performance of each attribute source.
QUESTIONS
- are attribute names case insensitive? YES according to PD1.5 behavior
api - public interface
need to think/design the query builder API, something fluent would be good
http://static.springsource.org/spring-ldap/site/apidocs/org/springframework/ldap/filter/package-frame.html
do we need an Attribute class or are Attributes just Strings?
Complex queries and multiple attribute sources
default root query object ORs its parts together?
break root query object up by OR clause?
the problem:
Given a query like (firstName=Jane && (isStudent=Y || lastName=Doe))
How do we handle sources that do not support all of the attributes in the query?
do a multi pass query, query sources that support all attributes first
query sources that support a subset of the attributes second, during merge filter these in code using the attributes that were not passed to the source
query non-searchable sources
General Query Logic
attribute query
ex: by username, [foo=bar, name=smith, ....]
Run MS & PS sources
turn map into OR() criteria for MS
Run S sources once per existing result
criteria query
ex: (firstName=jane && (lastName==smith || lastName=doe))
Run MS sources
merge results
Run PS sources
merge results
Run S sources once per existing result
attribute source classes - how do we tell/config the difference?
fully searchable (MS) - CriteriaSearchAttributeSource
uses a query template (supports arbitrary logic)
ldap or primary use directories go here
partial searchable (PS) - SimpleSearchAttributeSource
uses named placeholders but still can return multiple people for one query
small associated sources go here
single-person only (S)
will only ever return a single result ... is this useful?
in=memory sources like for shib go here
spi - what code in support implements to provide data
core - big ugly guts
core code that does
dependency tree calc of sources
determine query order and potential for parallelism, probably better to figure it with always parallel and having "block" spots that wait for other sources to complete
caching of results from each source
handling of query timeouts
merging results from various sources
mapping attribute names from the API side to the SPI side
jmx metrics for per-source usage & performance
primaryId
Used when a find person by primary id query is run
Used to merge data from multiple sources (each result must have a primaryId set)
add a list of AttributeSourceFilter
these are called in order (sorted by ordered)
if any filter returns false the filtered source is not executed
filterchain style API that allows for modification of search?
dependency tree calculation on configured attribute sources
needs to fail to init if something is wrong with the tree
this probably needs to be calculated and cached for each query since the tree will look different every time based on the input
caching of results - part of XML config support
for each configured source, set cache name or reference to Ehcache bean
optional cache name/ref for misses
optional cache name/ref for exceptions
query timeout - part of XML config support
set maximum wait for query result
set behavior on timeout? (ignore, fail)
merge behavior - part of XML config
does it work for each source to have a "prepend/append/overwrite" flag?
if so we probably need support for Spring's Orderable on the SPI impl
attribute name mapping - part of XML config support
for each configured source, option to allow for saying api attr "username" is actually "uid" in this spi
attribute lists
- in the config are these the PD side or the source side of the attr mapping?
- at least one required or optional search attribute must be specified
required search
ALL of these attributes must be include in a query for this source to be able to run the query
optional search
This plus the required set make up the collection of attributes that can be used to search, attributes outside this set are ignored
available return
The list of attributes the source returns, this is a best-effort set and the source may return more attributes than are named in the set
support
attribute sources
jdbc (MS,MP,S)
single row
multi row
ldap (MS,MP,S)
xml (MS)
request attribute (S)
filters
regex
spel