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Posted to commits@couchdb.apache.org by ko...@apache.org on 2019/12/19 01:01:18 UTC
[couchdb-smoosh] branch master updated: Add tombstone to this repo
This is an automated email from the ASF dual-hosted git repository.
kocolosk pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/couchdb-smoosh.git
The following commit(s) were added to refs/heads/master by this push:
new 45bca6f Add tombstone to this repo
45bca6f is described below
commit 45bca6fd815a1e69e70861eccad4be368b03a155
Author: Adam Kocoloski <ko...@apache.org>
AuthorDate: Wed Dec 18 20:01:11 2019 -0500
Add tombstone to this repo
---
README.md | 141 +-------------------------------------------------------------
1 file changed, 1 insertion(+), 140 deletions(-)
diff --git a/README.md b/README.md
index 9f9a480..5e79108 100644
--- a/README.md
+++ b/README.md
@@ -1,140 +1 @@
-Smoosh
-======
-
-Smoosh is CouchDB's auto-compaction daemon. It is notified when
-databases and views are updated and may then elect to enqueue them for
-compaction.
-
-API
----
-
-All API functions are in smoosh.erl and only the exported functions in
-this module should be called from outside of the smoosh application.
-
-Additionally, smoosh responds to config changes dynamically and these
-changes are the principal means of interacting with smoosh.
-
-Top-Level Settings
-------------------
-
-The main settings one interacts with are:
-
-<dl>
-<dt>db_channels<dd>A comma-separated list of channel names for
-databases.
-<dt>view_channels<dd>A comma-separated list of channel names for
-views.
-<dt>staleness<dd>The number of minutes that the (expensive) priority
-calculation can be stale for before it is recalculated. Defaults to 5.
-</dl>
-
-Sometimes it's necessary to use the following:
-
-<dl>
-<dt>cleanup_index_files</dt><dd>Whether smoosh cleans up the files
-for indexes that have been deleted. Defaults to false and probably
-shouldn't be changed unless the cluster is running low on disk space,
-and only after considering the ramifications.</dd>
-<dt>wait_secs</dt><dd>The time a channel waits before starting compactions
-to allow time to observe the system and make a smarter decision about what
-to compact first. Hardly ever changed from the default. Default 30 (seconds).
-</dd>
-</dl>
-
-Channel Settings
-----------------
-
-A channel has several important settings that control runtime
-behavior.
-
-<dl>
-<dt>capacity<dd>The maximum number of items the channel can hold (lowest priority item is removed to make room for new items). Defaults to 9999.
-<dt>concurrency<dd>The maximum number of jobs that can run concurrently. Defaults to 1.
-<dt>max_priority<dd>The item must have a priority lower than this to be enqueued. Defaults to infinity.
-<dt>max_size<dd>The item must be no larger than this many bytes in length to be enqueued. Defaults to infinity.
-<dt>min_priority<dd>The item must have a priority at least this high to be enqueued. Defaults to 5.0 for ratio and 16 mb for slack.
-<dt>min_changes<dd>The minimum number of changes since last compaction before the item will be enqueued. Defaults to 0. Currently only works for databases.
-<dt>min_size<dd>The item must be at least this many bytes in length to be enqueued. Defaults to 1mb (1048576 bytes).
-<dt>priority<dd>The method used to calculate priority. Can be ratio (calculated as disk_size/data_size) or slack (calculated as disk_size-data_size). Defaults to ratio.
-</dl>
-
-Structure
----------
-
-Smoosh consists of a central gen_server (smoosh_server) which manages
-a number of subordinate smoosh_channel gen_servers. This is not
-properly managed by OTP yet.
-
-Compaction Scheduling Algorithm
--------------------------------
-
-Smoosh decides whether to compact a database or view by evaluating the
-item against the selection criteria of each _channel_ in the order
-they are configured. By default there are two channels for databases
-("ratio_dbs" and "slack_dbs"), and two channels for views ("ratio_views"
-and "slack_views")
-
-Smoosh will enqueue the new item to the first channel that accepts
-it. If none accept it, the item is not enqueued for compaction.
-
-Notes on the data_size value
-----------------------------
-
-Every database and view shard has a data_size value. In CouchDB this
-accurately reflects the post-compaction file size. In DbCore, it is
-the size of the file that we bill for. It excludes the b+tree and
-database footer overhead. We also bill customers for the uncompressed
-size of their documents, though we store them compressed on disk.
-These two systems were developed independently (ours predates
-CouchDB's) and DbCore only calculates the billing size value.
-
-Because of the way our data_size is currently calculated, it can
-sometimes be necessary to enqueue databases and views with very low
-ratios. Due to this, it is also currently impossible to tell how
-optimally compacted a cluster is.
-
-Example config commands
------------------------
-
-Change the set of database channels;
-
- config:set("smoosh", "db_channels", "small_dbs,medium_dbs,large_dbs").
-
-Change the set of database channels on all live nodes in the cluster;
-
- rpc:multicall(config, set, ["smoosh", "db_channels", "small_dbs,medium_dbs,large_dbs"]).
-
-Change the concurrency of the ratio_dbs database channel to 2
-
- config:set("smoosh.ratio_dbs", "concurrency", "2").
-
-Change it on all live nodes in the cluster;
-
- rpc:multicall(config, set, ["smoosh.ratio_dbs", "concurrency", "2"]).
-
-Example API commands
---------------------
-
-smoosh:status()
-
-This prints the state of each channel; how many jobs they are
-currently running and how many jobs are enqueued (as well as the
-lowest and highest priority of those enqueued items). The idea is to
-provide, at a glance, sufficient insight into smoosh that an operator
-can assess whether smoosh is adequately targeting the reclaimable
-space in the cluster. In general, a healthy status output will have
-items in the ratio_dbs and ratio_views channels. Owing to the default
-settings, the slack_dbs and slack_views will almost certainly have
-items in them. Historically, we've not found that the slack channels,
-on their own, are particularly adept at keeping things well compacted.
-
-smoosh:enqueue_all_dbs(), smoosh:enqueue_all_views()
-
-These functions do just what they say but should not generally need to
-be called, smoosh is supposed to be autonomous. Call them if you get
-alerted to a disk space issue, they might well help. If they do, that
-indicates a bug in smoosh as it should already have enqueued eligible
-shards once they met the configured settings.
-
-
-
+Smoosh is CouchDB's auto-compaction daemon. This repository was merged into the main CouchDB repo as of 78eba8 - see [apache/couchdb#2326](https://github.com/apache/couchdb/pull/2326).