I have a web application where users submit queries to a Lucene index. The queries
are parsed by a Lucene
QueryParser
. I learned the hard way that QueryParser
is not thread-safe.
Is it better to use a single QueryParser
instance, and synchronize on calls to its parse()
method? Or is it better to construct a new instance for each query? (Or would I be better served by a pool of QueryParser
s?)
I know that in general questions like this depend on the particulars and require profiling, but maybe someone out there can say definitively "QueryParser
s are extremely inexpensive/expensive to construct"?