Merge pull request #30 from miguelmatosduarte/use_zookeeper_stats_names_instead_of_hardcoded_line_numbers_in_checks

Grab `mntr` output stats by name instead of line number in Zookeeper checks

Author: Jef Spaleta

bin/check-zookeeper-file-descriptors.rb

@@ -70,7 +70,7 @@ def run
       end
 
       result = ready.first.first.read.chomp.split("\n")
-      avg_fd = (result[13].split("\t")[1].to_f / result[14].split("\t")[1].to_f)
+      avg_fd = (result.grep(/zk_open_file_descriptor_count/)[0].split("\t")[1].to_f / result.grep(/zk_max_file_descriptor_count/)[0].split("\t")[1].to_f)
 
       ok %(Zookeeper's open file descriptors rate is #{avg_fd}) if avg_fd < config[:fd_critical]
       critical %(Zookeeper's open file descriptors rate is #{avg_fd}, which is more than #{config[:fd_critical]} threshold)

bin/check-zookeeper-latency.rb

@@ -67,7 +67,7 @@ def run
       end
 
       result = ready.first.first.read.chomp.split("\n")
-      avg_latency = result[1].split("\t")[1].to_i
+      avg_latency = result.grep(/zk_avg_latency/)[0].split("\t")[1].to_i
 
       ok %(Zookeeper has average latency #{avg_latency}) if avg_latency < config[:avg_latency_critical]
       critical %(Zookeeper's average latency is #{avg_latency}, which is more than #{config[:avg_latency_critical]} threshold)

bin/check-zookeeper-reqs.rb

@@ -70,7 +70,7 @@ def run
       end
 
       result = ready.first.first.read.chomp.split("\n")
-      out_reqs = result[7].split("\t")[1].to_i
+      out_reqs = result.grep(/zk_outstanding_requests/)[0].split("\t")[1].to_i
 
       ok %(Zookeeper has #{out_reqs} outstanding requests) if out_reqs < config[:out_reqs_critical]
       critical %(Zookeeper has #{out_reqs} outstanding requests, which is more than #{config[:out_reqs_critical]} threshold)