public class WarmUpTask extends Object implements Callable<Map<String,BaseIndexStats>>
|Constructor and Description|
public WarmUpTask(Journal journal, List<String> namespaces, long timestamp, int nparallel, boolean visitLeaves)
journal- The journal.
namespaces- A list of zero or more namespaces to be warmed up (optional). When
nullor empty, all namespaces will be warmed up.
timestamp- The commit time to be warmed up and -or-
ITx.READ_COMMITTEDto warm up the last commit point on the journal.
nparallel- The #of threads that will be used to scan the pages in the indices associated with those namespaces (GTE ONE). The indices will be scanned with one thread per index. This parameter determines the #of such scans that will execute in parallel. Since the thread will block on any IO, you need a modestly large number of threads here to enqueue enough disk reads to drive enough IOPs for an efficient disk scan. Even a slow disk should use at least 10 threads.
truethe leaves of the indices will also be read (the recommended warm up procedure does not read the leaves).
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