Package dev.hardwood.jfr

package dev.hardwood.jfr

Java Flight Recorder (JFR) events for diagnosing read performance.

Events are emitted during file opening, page decoding, row group filtering, and batch prefetching. Enable them via JFR configuration or the jdk.jfr.consumer API to monitor I/O patterns and identify bottlenecks in production.

  • Classes
    Class
    Description
    BatchWaitEvent
    JFR event emitted when the consumer thread blocks waiting for a batch to be assembled by the assembly thread.
    FileMappingEvent
    JFR event emitted when Hardwood memory-maps a region of a Parquet file.
    FileOpenedEvent
    JFR event emitted when a Parquet file is opened and its metadata is read.
    PageDecodedEvent
    JFR event emitted when a single Parquet data page is decoded.
    PageFilterEvent
    JFR event emitted when pages are filtered by Column Index predicate push-down.
    PrefetchMissEvent
    JFR event emitted when the prefetch queue cannot supply a decoded page in time.
    RecordFilterEvent
    JFR event emitted when records are filtered by record-level predicate evaluation.
    RowGroupFilterEvent
    JFR event emitted when row groups are filtered by a predicate push-down filter.
    RowGroupScannedEvent
    JFR event emitted when all pages in a row group column chunk have been scanned.