lib/logstash/inputs/snmp/base_client.rb in logstash-input-snmp-1.2.2 vs lib/logstash/inputs/snmp/base_client.rb in logstash-input-snmp-1.2.3

@@ -5,37 +5,67 @@
 
 module LogStash
   class SnmpClientError < StandardError
   end
 
-  class BaseSnmpClient
-
+  # Only one Snmp instance per transport should be created and listened on.
+  # The Snmp object is thread safe and can be shared across input threads and pipelines.
+  class SnmpFactory
     java_import "org.snmp4j.Snmp"
+    java_import "org.snmp4j.transport.DefaultUdpTransportMapping"
+    java_import "org.snmp4j.transport.DefaultTcpTransportMapping"
+
+    include Singleton
+
+    def initialize
+      @lock = Mutex.new
+      @udp = nil
+      @tcp = nil
+    end
+
+    def udp
+      @lock.synchronize do
+        if @udp.nil?
+          @udp = Snmp.new(DefaultUdpTransportMapping.new)
+          @udp.listen
+        end
+      end
+      @udp
+    end
+
+    def tcp
+      @lock.synchronize do
+        if @tcp.nil?
+          @tcp = Snmp.new(DefaultTcpTransportMapping.new)
+          @tcp.listen
+        end
+      end
+      @tcp
+    end
+  end
+
+  class BaseSnmpClient
     java_import "org.snmp4j.TransportMapping"
     java_import "org.snmp4j.mp.SnmpConstants"
     java_import "org.snmp4j.smi.OID"
     java_import "org.snmp4j.smi.VariableBinding"
-    java_import "org.snmp4j.transport.DefaultUdpTransportMapping"
-    java_import "org.snmp4j.transport.DefaultTcpTransportMapping"
     java_import "org.snmp4j.util.TableUtils"
     java_import "org.snmp4j.util.TreeUtils"
     java_import "org.snmp4j.asn1.BER"
 
     include LogStash::Util::Loggable
 
     def initialize(protocol, address, port, retries, timeout, mib)
+      @mib = mib
+
       transport = case protocol.to_s
         when "udp"
-          DefaultUdpTransportMapping.new
+          @snmp = SnmpFactory.instance.udp
         when "tcp"
-          DefaultTcpTransportMapping.new
+          @snmp = SnmpFactory.instance.tcp
         else
           raise(SnmpClientError, "invalid transport protocol specified '#{protocol.to_s}', expecting 'udp' or 'tcp'")
-        end
-
-      @mib = mib
-      @snmp = Snmp.new(transport)
-      transport.listen()
+      end
     end
 
     def get(oids, strip_root = 0, path_length = 0)
       pdu = get_pdu
       Array(oids).each { |oid| pdu.add(VariableBinding.new(OID.new(oid))) }