require 'rubygems'
require 'redis'
+ClusterHashSlots = 4096
+
def xputs(s)
printf s
STDOUT.flush
def initialize(addr)
s = addr.split(":")
if s.length != 2
- puts "Invalid node name #{node}"
+ puts "Invalid node name #{addr}"
exit 1
end
+ @r = nil
@host = s[0]
@port = s[1]
+ @slots = {}
+ @dirty = false
end
def to_s
"#{@host}:#{@port}"
end
- def connect
+ def connect(o={})
xputs "Connecting to node #{self}: "
begin
- @r = Redis.new(:host => @ost, :port => @port)
+ @r = Redis.new(:host => @host, :port => @port)
@r.ping
rescue
puts "ERROR"
puts "Sorry, can't connect to node #{self}"
+ exit 1 if o[:abort]
+ @r = nil
end
puts "OK"
end
end
end
+ def assert_empty
+ if !(@r.cluster("info").split("\r\n").index("cluster_known_nodes:1")) ||
+ (@r.info['db0'])
+ puts "Error: Node #{self} is not empty. Either the node already knows other nodes (check with nodes-info) or contains some key in database 0."
+ exit 1
+ end
+ end
+
+ def add_slots(slots)
+ slots.each{|s|
+ @slots[s] = :new
+ }
+ @dirty = true
+ end
+
+ def flush_node_config
+ return if !@dirty
+ new = []
+ @slots.each{|s,val|
+ if val == :new
+ new << s
+ @slots[s] = true
+ end
+ }
+ @r.cluster("addslots",*new)
+ @dirty = false
+ end
+
+ def info_string
+ # We want to display the hash slots assigned to this node
+ # as ranges, like in: "1-5,8-9,20-25,30"
+ #
+ # Note: this could be easily written without side effects,
+ # we use 'slots' just to split the computation into steps.
+
+ # First step: we want an increasing array of integers
+ # for instance: [1,2,3,4,5,8,9,20,21,22,23,24,25,30]
+ slots = @slots.keys.sort
+
+ # As we want to aggregate adiacent slots we convert all the
+ # slot integers into ranges (with just one element)
+ # So we have something like [1..1,2..2, ... and so forth.
+ slots.map!{|x| x..x}
+
+ # Finally we group ranges with adiacent elements.
+ slots = slots.reduce([]) {|a,b|
+ if !a.empty? && b.first == (a[-1].last)+1
+ a[0..-2] + [(a[-1].first)..(b.last)]
+ else
+ a + [b]
+ end
+ }
+
+ # Now our task is easy, we just convert ranges with just one
+ # element into a number, and a real range into a start-end format.
+ # Finally we join the array using the comma as separator.
+ slots = slots.map{|x|
+ x.count == 1 ? x.first.to_s : "#{x.first}-#{x.last}"
+ }.join(",")
+
+ "#{self.to_s.ljust(25)} slots:#{slots}"
+ end
+
+ def info
+ {
+ :host => @host,
+ :port => @port,
+ :slots => @slots,
+ :dirty => @dirty
+ }
+ end
+
+ def is_dirty?
+ @dirty
+ end
+
def r
@r
end
end
class RedisTrib
+ def initialize
+ @nodes = []
+ end
+
def check_arity(req_args, num_args)
if ((req_args > 0 and num_args != req_args) ||
(req_args < 0 and num_args < req_args.abs))
end
end
- def create_cluster
+ def add_node(node)
+ @nodes << node
+ end
+
+ def check_cluster
+ puts "Performing Cluster Check (using node #{@nodes[0]})"
+ show_nodes
+ end
+
+ def alloc_slots
+ slots_per_node = ClusterHashSlots/@nodes.length
+ i = 0
+ @nodes.each{|n|
+ first = i*slots_per_node
+ last = first+slots_per_node-1
+ last = ClusterHashSlots-1 if i == @nodes.length-1
+ n.add_slots first..last
+ i += 1
+ }
+ end
+
+ def flush_nodes_config
+ @nodes.each{|n|
+ n.flush_node_config
+ }
+ end
+
+ def show_nodes
+ @nodes.each{|n|
+ puts n.info_string
+ }
+ end
+
+ def join_cluster
+ # We use a brute force approach to make sure the node will meet
+ # each other, that is, sending CLUSTER MEET messages to all the nodes
+ # about the very same node.
+ # Thanks to gossip this information should propagate across all the
+ # cluster in a matter of seconds.
+ first = false
+ @nodes.each{|n|
+ if !first then first = n.info; next; end # Skip the first node
+ n.r.cluster("meet",first[:host],first[:port])
+ }
+ end
+
+ def yes_or_die(msg)
+ print "#{msg} (type 'yes' to accept): "
+ STDOUT.flush
+ if !(STDIN.gets.chomp.downcase == "yes")
+ puts "Aborting..."
+ exit 1
+ end
+ end
+
+ # redis-trib subcommands implementations
+
+ def check_cluster_cmd
+ node = ClusterNode.new(ARGV[1])
+ node.connect(:abort => true)
+ node.assert_cluster
+ add_node(node)
+ check_cluster
+ end
+
+ def create_cluster_cmd
puts "Creating cluster"
ARGV[1..-1].each{|n|
node = ClusterNode.new(n)
- node.connect
+ node.connect(:abort => true)
node.assert_cluster
- # node.assert_empty
+ node.assert_empty
+ add_node(node)
}
+ puts "Performing hash slots allocation on #{@nodes.length} nodes..."
+ alloc_slots
+ show_nodes
+ yes_or_die "Can I set the above configuration?"
+ flush_nodes_config
+ puts "** Nodes configuration updated"
+ puts "** Sending CLUSTER MEET messages to join the cluster"
+ join_cluster
+ check_cluster
end
end
COMMANDS={
- "create-cluster" => ["create_cluster", -2]
+ "create" => ["create_cluster_cmd", -2, "host1:port host2:port ... hostN:port"],
+ "check" => ["check_cluster_cmd", 2, "host:port"]
}
# Sanity check
if ARGV.length == 0
puts "Usage: redis-trib <command> <arguments ...>"
+ puts
+ COMMANDS.each{|k,v|
+ puts " #{k.ljust(20)} #{v[2]}"
+ }
+ puts
exit 1
end