From f53d3b51327f7498c0e87644b7ce64800b86fd9d Mon Sep 17 00:00:00 2001 From: Martin Thompson Date: Sat, 12 Oct 2019 09:32:00 +0100 Subject: [PATCH] Update README.md --- aeron-archive/README.md | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/aeron-archive/README.md b/aeron-archive/README.md index c24d1e57d7..8d8194fff3 100644 --- a/aeron-archive/README.md +++ b/aeron-archive/README.md @@ -30,7 +30,8 @@ Features: live stream for cut over if the consumer is fast enough to keep up. - **Replicate:** recordings can be replicated from a source to destination archive with the option to follow on with - a live stream when the source is multicast. + a live stream when the source is multicast. When using replication it is necessary to configure the replication channel for + thedestination archive with `aeron.archive.replication.channel`. Usage ===== @@ -62,6 +63,21 @@ Recording Signal Events On a control session signals can be tracked for when a recording starts and stop plus other operations like extend, replicate, and live merge. +Recording Durability +---- +An archive can be instructed to record streams, i.e. `` pairs. These streams are recorded with the file sync level the archive has been launched with. Progress is reported on the recording events stream. + +- `aeron.archive.file.sync.level=0`: for normal writes to the OS page cache for background writing to disk. +- `aeron.archive.file.sync.level=1`: for forcing the dirty data pages to disk. +- `aeron.archive.file.sync.level=2`: for forcing the dirty data pages and file metadata to disk. + +When setting file sync level greater than zero it is also important to sync the archive catalog with the + `aeron.archive.catalog.file.sync.level` to the same value. + +Recordings will be assigned a `recordingId` and a full description of the stream is captured in the Archive Catalog. The Catalog chronicles the contents of an archive as `RecordingDescriptor`s which can be queried. + +The progress of active recordings can be tracked using `AeronStat` to view the `rec-pos` counter for each stream. + Persisted Format ===== The Archive is backed by 3 file types, all of which are expected to reside in the `archiveDir`.