CouchDB database and views compaction script. Save in /usr/local/bin and cron it. Protip: https://coderwall.com/p/q-sjhw

couchdb-compact.rb

#!/usr/bin/env ruby

# CouchDB compaction script - fetches the list of all databases from
# a running couchdb instance and issues the compaction command for each
# one of them, and for each design view into them.

# Read more about compaction here:
#   http://wiki.apache.org/couchdb/Compaction

#  - [email protected]  Wed Nov 30 18:19:27 CET 2011

require 'net/http'

require 'rubygems'
require 'json'

$HOST = 'localhost'
$PORT = 5984
$USER = 'username'
$PASS = 'password'

# Creates an HTTP request with the given method and for the given
# URL. Sets the Content-Type header to application/json and the
# HTTP basic auth credentials specified above.
#
def r(method, url)
  klass = Net::HTTP.const_get(method.to_s.capitalize)
  klass.new(url, 'Content-Type' => 'application/json').tap do |req|
    req.basic_auth $USER, $PASS
  end
end

def get(url)
  JSON.parse($http.request(r(:get, url)).body)
end

def post(url)
  JSON.parse($http.request(r(:post, url)).body)['ok']
end

def size(db)
  "%.2f MB" % (get("/#{db}")['disk_size'].to_i / 1024.0 / 1024.0)
end

# Connects to the database server
$http = Net::HTTP.new($HOST, $PORT)

# Gets the list of all databases
databases = get('/_all_dbs').reject {|d| d =~ /^_/}

# For each database
databases.each do |database|

  # Get list of database views
  puts "Processing #{database} - #{size(database)}"

  url   = "/#{database}/_all_docs?startkey=\"_design\"&endkey=\"_design0\""
  views = get(url)['rows'].map {|r| r['id'].sub('_design/', '')}

  # For each view
  views.each do |view|
    # Issue the compaction request
    post("/#{database}/_compact/#{view}")
  end

  # Issue the compaction request
  post("/#{database}/_compact")
end

puts
puts "Waiting for compaction to finish..."
puts

sleep 1 while get('/_active_tasks').size > 0
 
databases.each do |database|
  puts "Processed #{database} - #{size(database)}"
end

Nice! Note that 1.2 and higher have an automatic compaction engine built in - might be even easier for you: https://github.com/apache/couchdb/blob/1.2.0/etc/couchdb/default.ini.tpl.in#L230