# Is Elasticsearch a drop in replacement for Memcached? **URL:** \ **Category:** Elasticsearch\ **Created:** [October 1, 2014, 1:35pm UTC](https://discuss.elastic.co/t/is-elasticsearch-a-drop-in-replacement-for-memcached/20024 "2014-10-01T13:35:40Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Ryan\_Bergman](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ryan_bergman/32/1234_2.png) [@Ryan\_Bergman](https://discuss.elastic.co/u/Ryan_Bergman)\ **Post date:** [October 1, 2014, 1:35pm UTC](https://discuss.elastic.co/t/is-elasticsearch-a-drop-in-replacement-for-memcached/20024/1 "2014-10-01T13:35:40Z")
Hi, I've been trying to play with Elasticsearch as a drop in replacement for Memcached. I've installed the memcached transport and it looks like it started fine and is on the right port. However if I attempt to use the java spy.memcahed client library I'm not able to cache things. Instead I get errors like: 2014-10-01 08:22:31.579 INFO net.spy.memcached.MemcachedConnection: Added {QA sa=localhost/127.0.0.1:11211, #Rops=0, #Wops=0, #iq=0, topRop=null, topWop=null, toWrite=0, interested=0} to connect queue 2014-10-01 08:22:31.586 INFO net.spy.memcached.MemcachedConnection: Connection state changed for sun.nio.ch.SelectionKeyImpl@76fb509a 2014-10-01 08:22:31.679 INFO net.spy.memcached.MemcachedConnection: Reconnecting due to exception on {QA sa=localhost/127.0.0.1:11211, #Rops=2, #Wops=0, #iq=0, topRop=Cmd: 2 Opaque: 2 Key: foo Cas: 0 Exp: 1000 Flags: 0 Data Length: 3, topWop=null, toWrite=0, interested=1} java.io.IOException: Disconnected unexpected, will reconnect. over and over. On the Elasticsearch side I get an error of [2014-10-01 08:22:31,675][ERROR][memcached.netty] [Living Hulk] Unsupported opcode [0x2], ignoring and closing connection Here is my client configuration: ConnectionFactoryBuilder factory = new ConnectionFactoryBuilder(); factory.setProtocol(ConnectionFactoryBuilder.Protocol.BINARY); SerializingTranscoder t = new SerializingTranscoder(1000000); t.setCompressionThreshold(1024); factory.setTranscoder(t); factory.setOpTimeout(1000); factory.setTimeoutExceptionThreshold(1998); factory.setHashAlg(DefaultHashAlgorithm.KETAMA\_HASH); factory.setLocatorType(ConnectionFactoryBuilder.Locator.CONSISTENT); factory.setFailureMode(FailureMode.Redistribute); factory.setUseNagleAlgorithm(false); -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/c2b7c8d0-ff79-488c-b3c5-b8ca337bd955%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/c2b7c8d0-ff79-488c-b3c5-b8ca337bd955%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Tanguy\_Leroux](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/tanguy_leroux/32/121066_2.png) [@Tanguy\_Leroux](https://discuss.elastic.co/u/Tanguy_Leroux)\ **Post date:** [October 2, 2014, 7:27am UTC](https://discuss.elastic.co/t/is-elasticsearch-a-drop-in-replacement-for-memcached/20024/2 "2014-10-02T07:27:58Z")
Hi, Which versions of elasticsearch / elasticsearch-transport-memcached / memcached are you using? It looks like the memcached client is trying to execute a 0x02 ADD command whereas the elasticsearch-transport-memcached only supports get/set/delete/quit commands and disconnects for all others (see documentation here: [GitHub - elastic/elasticsearch-transport-memcached: memcached transport plugin for elasticsearch (STOPPED)](https://github.com/elasticsearch/elasticsearch-transport-memcached)) You may try a "set" instead. -- Tanguy Le mercredi 1 octobre 2014 15:35:40 UTC+2, Ryan Bergman a écrit : > Hi, > I've been trying to play with Elasticsearch as a drop in replacement > for Memcached. I've installed the memcached transport and it looks like it > started fine and is on the right port. However if I attempt to use the java > spy.memcahed client library I'm not able to cache things. > > Instead I get errors like: > > 2014-10-01 08:22:31.579 INFO net.spy.memcached.MemcachedConnection: Added > {QA sa=localhost/127.0.0.1:11211, #Rops=0, #Wops=0, #iq=0, topRop=null, > topWop=null, toWrite=0, interested=0} to connect queue > 2014-10-01 08:22:31.586 INFO net.spy.memcached.MemcachedConnection: > Connection state changed for sun.nio.ch.SelectionKeyImpl@76fb509a > 2014-10-01 08:22:31.679 INFO net.spy.memcached.MemcachedConnection: > Reconnecting due to exception on {QA sa=localhost/127.0.0.1:11211, > #Rops=2, #Wops=0, #iq=0, topRop=Cmd: 2 Opaque: 2 Key: foo Cas: 0 Exp: 1000 > Flags: 0 Data Length: 3, topWop=null, toWrite=0, interested=1} > java.io.IOException: Disconnected unexpected, will reconnect. > > over and over. > > On the Elasticsearch side I get an error of > [2014-10-01 08:22:31,675][ERROR][memcached.netty] [Living Hulk] > Unsupported opcode [0x2], ignoring and closing connection > > Here is my client configuration: > ConnectionFactoryBuilder factory = new ConnectionFactoryBuilder(); > factory.setProtocol(ConnectionFactoryBuilder.Protocol.BINARY); > SerializingTranscoder t = new SerializingTranscoder(1000000); > t.setCompressionThreshold(1024); > factory.setTranscoder(t); > factory.setOpTimeout(1000); > factory.setTimeoutExceptionThreshold(1998); > factory.setHashAlg(DefaultHashAlgorithm.KETAMA\_HASH); > > factory.setLocatorType(ConnectionFactoryBuilder.Locator.CONSISTENT); > factory.setFailureMode(FailureMode.Redistribute); > factory.setUseNagleAlgorithm(false); -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/139a935a-fbc5-48fa-ab33-1a4c0cde4397%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/139a935a-fbc5-48fa-ab33-1a4c0cde4397%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Ryan\_Bergman](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ryan_bergman/32/1234_2.png) [@Ryan\_Bergman](https://discuss.elastic.co/u/Ryan_Bergman)\ **Post date:** [October 2, 2014, 2:12pm UTC](https://discuss.elastic.co/t/is-elasticsearch-a-drop-in-replacement-for-memcached/20024/3 "2014-10-02T14:12:29Z")
I'm using 1.3.3 with a transport of 2.3.0 I was attempting to use one of the standard common Memcache client libraries that already exist. I was hoping that they would "just work" without having to write my own client (or modifying one of them). It sounds like that's not an option. Is there a plan for the transport to support ADD in the future? Ryan On Thursday, October 2, 2014 2:27:58 AM UTC-5, Tanguy Leroux wrote: > Hi, > > Which versions of elasticsearch / elasticsearch-transport-memcached / > memcached are you using? > > It looks like the memcached client is trying to execute a 0x02 ADD command > whereas the elasticsearch-transport-memcached only supports > get/set/delete/quit commands and disconnects for all others (see > documentation here: > [GitHub - elastic/elasticsearch-transport-memcached: memcached transport plugin for elasticsearch (STOPPED)](https://github.com/elasticsearch/elasticsearch-transport-memcached)) > > You may try a "set" instead. > > -- Tanguy > > Le mercredi 1 octobre 2014 15:35:40 UTC+2, Ryan Bergman a écrit : > > > Hi, > > I've been trying to play with Elasticsearch as a drop in replacement > > for Memcached. I've installed the memcached transport and it looks like it > > started fine and is on the right port. However if I attempt to use the java > > spy.memcahed client library I'm not able to cache things. > > > > Instead I get errors like: > > > > 2014-10-01 08:22:31.579 INFO net.spy.memcached.MemcachedConnection: > > Added {QA sa=localhost/127.0.0.1:11211, #Rops=0, #Wops=0, #iq=0, > > topRop=null, topWop=null, toWrite=0, interested=0} to connect queue > > 2014-10-01 08:22:31.586 INFO net.spy.memcached.MemcachedConnection: > > Connection state changed for sun.nio.ch.SelectionKeyImpl@76fb509a > > 2014-10-01 08:22:31.679 INFO net.spy.memcached.MemcachedConnection: > > Reconnecting due to exception on {QA sa=localhost/127.0.0.1:11211, > > #Rops=2, #Wops=0, #iq=0, topRop=Cmd: 2 Opaque: 2 Key: foo Cas: 0 Exp: 1000 > > Flags: 0 Data Length: 3, topWop=null, toWrite=0, interested=1} > > java.io.IOException: Disconnected unexpected, will reconnect. > > > > over and over. > > > > On the Elasticsearch side I get an error of > > [2014-10-01 08:22:31,675][ERROR][memcached.netty] [Living Hulk] > > Unsupported opcode [0x2], ignoring and closing connection > > > > Here is my client configuration: > > ConnectionFactoryBuilder factory = new ConnectionFactoryBuilder(); > > factory.setProtocol(ConnectionFactoryBuilder.Protocol.BINARY); > > SerializingTranscoder t = new SerializingTranscoder(1000000); > > t.setCompressionThreshold(1024); > > factory.setTranscoder(t); > > factory.setOpTimeout(1000); > > factory.setTimeoutExceptionThreshold(1998); > > factory.setHashAlg(DefaultHashAlgorithm.KETAMA\_HASH); > > > > factory.setLocatorType(ConnectionFactoryBuilder.Locator.CONSISTENT); > > factory.setFailureMode(FailureMode.Redistribute); > > factory.setUseNagleAlgorithm(false); -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/f11aa1c9-17bc-4a30-8c97-bf09c003989e%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/f11aa1c9-17bc-4a30-8c97-bf09c003989e%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Tanguy\_Leroux](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/tanguy_leroux/32/121066_2.png) [@Tanguy\_Leroux](https://discuss.elastic.co/u/Tanguy_Leroux)\ **Post date:** [October 2, 2014, 2:36pm UTC](https://discuss.elastic.co/t/is-elasticsearch-a-drop-in-replacement-for-memcached/20024/4 "2014-10-02T14:36:02Z")
You don't need to write your own client, just to use SET commands instead of ADD. For example, with the spymemcached library you should do something like: MemcachedClient c=new MemcachedClient( new InetSocketAddress("hostname", portNum)); // Store a value (async) for one hour c.set("someKey", 3600, someObject); // Retrieve a value (synchronously). Object myObject=c.get("someKey"); -- Tanguy Le jeudi 2 octobre 2014 16:12:29 UTC+2, Ryan Bergman a écrit : > I'm using 1.3.3 with a transport of 2.3.0 > > I was attempting to use one of the standard common Memcache client > libraries that already exist. I was hoping that they would "just work" > without having to write my own client (or modifying one of them). It sounds > like that's not an option. Is there a plan for the transport to support ADD > in the future? > > Ryan > > On Thursday, October 2, 2014 2:27:58 AM UTC-5, Tanguy Leroux wrote: > > > Hi, > > > > Which versions of elasticsearch / elasticsearch-transport-memcached / > > memcached are you using? > > > > It looks like the memcached client is trying to execute a 0x02 ADD > > command whereas the elasticsearch-transport-memcached only supports > > get/set/delete/quit commands and disconnects for all others (see > > documentation here: > > [GitHub - elastic/elasticsearch-transport-memcached: memcached transport plugin for elasticsearch (STOPPED)](https://github.com/elasticsearch/elasticsearch-transport-memcached)) > > > > You may try a "set" instead. > > > > -- Tanguy > > > > Le mercredi 1 octobre 2014 15:35:40 UTC+2, Ryan Bergman a écrit : > > > > > Hi, > > > I've been trying to play with Elasticsearch as a drop in replacement > > > for Memcached. I've installed the memcached transport and it looks like it > > > started fine and is on the right port. However if I attempt to use the java > > > spy.memcahed client library I'm not able to cache things. > > > > > > Instead I get errors like: > > > > > > 2014-10-01 08:22:31.579 INFO net.spy.memcached.MemcachedConnection: > > > Added {QA sa=localhost/127.0.0.1:11211, #Rops=0, #Wops=0, #iq=0, > > > topRop=null, topWop=null, toWrite=0, interested=0} to connect queue > > > 2014-10-01 08:22:31.586 INFO net.spy.memcached.MemcachedConnection: > > > Connection state changed for sun.nio.ch.SelectionKeyImpl@76fb509a > > > 2014-10-01 08:22:31.679 INFO net.spy.memcached.MemcachedConnection: > > > Reconnecting due to exception on {QA sa=localhost/127.0.0.1:11211, > > > #Rops=2, #Wops=0, #iq=0, topRop=Cmd: 2 Opaque: 2 Key: foo Cas: 0 Exp: 1000 > > > Flags: 0 Data Length: 3, topWop=null, toWrite=0, interested=1} > > > java.io.IOException: Disconnected unexpected, will reconnect. > > > > > > over and over. > > > > > > On the Elasticsearch side I get an error of > > > [2014-10-01 08:22:31,675][ERROR][memcached.netty] [Living > > > Hulk] Unsupported opcode [0x2], ignoring and closing connection > > > > > > Here is my client configuration: > > > ConnectionFactoryBuilder factory = new ConnectionFactoryBuilder(); > > > factory.setProtocol(ConnectionFactoryBuilder.Protocol.BINARY); > > > SerializingTranscoder t = new SerializingTranscoder(1000000); > > > t.setCompressionThreshold(1024); > > > factory.setTranscoder(t); > > > factory.setOpTimeout(1000); > > > factory.setTimeoutExceptionThreshold(1998); > > > factory.setHashAlg(DefaultHashAlgorithm.KETAMA\_HASH); > > > > > > factory.setLocatorType(ConnectionFactoryBuilder.Locator.CONSISTENT); > > > factory.setFailureMode(FailureMode.Redistribute); > > > factory.setUseNagleAlgorithm(false); -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/106b7c04-04db-499a-9204-6d57d72a7278%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/106b7c04-04db-499a-9204-6d57d72a7278%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Ryan\_Bergman](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ryan_bergman/32/1234_2.png) [@Ryan\_Bergman](https://discuss.elastic.co/u/Ryan_Bergman)\ **Post date:** [October 2, 2014, 2:59pm UTC](https://discuss.elastic.co/t/is-elasticsearch-a-drop-in-replacement-for-memcached/20024/5 "2014-10-02T14:59:42Z")
Sure, but I'll have to go through all the existing prod code that uses the client and change it to set. It would be nicer in the future if add was supported. I noticed there is a github issue for that [https://github.com/elasticsearch/elasticsearch-transport-memcached/issues/7](https://github.com/elasticsearch/elasticsearch-transport-memcached/issues/7) Also, in my test scenario I'm now having other issues with the spy.memcache client. It's a little obscure and happens on a get: 2014-10-02 09:53:08.931 INFO net.spy.memcached.MemcachedConnection: Reconnecting due to exception on {QA sa=localhost/127.0.0.1:11211, #Rops=1, #Wops=0, #iq=0, topRop=Cmd: 0 Opaque: 3 Key: foo, topWop=null, toWrite=0, interested=1} java.lang.ArrayIndexOutOfBoundsException: 0 at net.spy.memcached.protocol.binary.OperationImpl.decodeInt(OperationImpl.java:257) at net.spy.memcached.protocol.binary.GetOperationImpl.decodePayload(GetOperationImpl.java:51) at net.spy.memcached.protocol.binary.OperationImpl.finishedPayload(OperationImpl.java:178) at net.spy.memcached.protocol.binary.OperationImpl.readFromBuffer(OperationImpl.java:162) at net.spy.memcached.MemcachedConnection.handleReads(MemcachedConnection.java:463) at net.spy.memcached.MemcachedConnection.handleIO(MemcachedConnection.java:380) at net.spy.memcached.MemcachedConnection.handleIO(MemcachedConnection.java:242) at net.spy.memcached.MemcachedConnection.run(MemcachedConnection.java:836) Looks like it's happening in a method that is reading the binary data: static int decodeInt(byte data, int i) { return (data[i] & 0xff) \<\< 24 | (data[i + 1] & 0xff) \<\< 16 | (data[i + 2] & 0xff) \<\< 8 | (data[i + 3] & 0xff); } I'll try and dig in a little more and also maybe try another client like the Whalin client. Ryan On Thursday, October 2, 2014 9:36:02 AM UTC-5, Tanguy Leroux wrote: > You don't need to write your own client, just to use SET commands instead > of ADD. > > For example, with the spymemcached library you should do something like: > > MemcachedClient c=new MemcachedClient( > new InetSocketAddress("hostname", portNum)); > > // Store a value (async) for one hour > c.set("someKey", 3600, someObject); > // Retrieve a value (synchronously). > Object myObject=c.get("someKey"); > > -- Tanguy > > Le jeudi 2 octobre 2014 16:12:29 UTC+2, Ryan Bergman a écrit : > > > I'm using 1.3.3 with a transport of 2.3.0 > > > > I was attempting to use one of the standard common Memcache client > > libraries that already exist. I was hoping that they would "just work" > > without having to write my own client (or modifying one of them). It sounds > > like that's not an option. Is there a plan for the transport to support ADD > > in the future? > > > > Ryan > > > > On Thursday, October 2, 2014 2:27:58 AM UTC-5, Tanguy Leroux wrote: > > > > > Hi, > > > > > > Which versions of elasticsearch / elasticsearch-transport-memcached / > > > memcached are you using? > > > > > > It looks like the memcached client is trying to execute a 0x02 ADD > > > command whereas the elasticsearch-transport-memcached only supports > > > get/set/delete/quit commands and disconnects for all others (see > > > documentation here: > > > [GitHub - elastic/elasticsearch-transport-memcached: memcached transport plugin for elasticsearch (STOPPED)](https://github.com/elasticsearch/elasticsearch-transport-memcached)) > > > > > > You may try a "set" instead. > > > > > > -- Tanguy > > > > > > Le mercredi 1 octobre 2014 15:35:40 UTC+2, Ryan Bergman a écrit : > > > > > > > Hi, > > > > I've been trying to play with Elasticsearch as a drop in replacement > > > > for Memcached. I've installed the memcached transport and it looks like it > > > > started fine and is on the right port. However if I attempt to use the java > > > > spy.memcahed client library I'm not able to cache things. > > > > > > > > Instead I get errors like: > > > > > > > > 2014-10-01 08:22:31.579 INFO net.spy.memcached.MemcachedConnection: > > > > Added {QA sa=localhost/127.0.0.1:11211, #Rops=0, #Wops=0, #iq=0, > > > > topRop=null, topWop=null, toWrite=0, interested=0} to connect queue > > > > 2014-10-01 08:22:31.586 INFO net.spy.memcached.MemcachedConnection: > > > > Connection state changed for sun.nio.ch.SelectionKeyImpl@76fb509a > > > > 2014-10-01 08:22:31.679 INFO net.spy.memcached.MemcachedConnection: > > > > Reconnecting due to exception on {QA sa=localhost/127.0.0.1:11211, > > > > #Rops=2, #Wops=0, #iq=0, topRop=Cmd: 2 Opaque: 2 Key: foo Cas: 0 Exp: 1000 > > > > Flags: 0 Data Length: 3, topWop=null, toWrite=0, interested=1} > > > > java.io.IOException: Disconnected unexpected, will reconnect. > > > > > > > > over and over. > > > > > > > > On the Elasticsearch side I get an error of > > > > [2014-10-01 08:22:31,675][ERROR][memcached.netty] [Living > > > > Hulk] Unsupported opcode [0x2], ignoring and closing connection > > > > > > > > Here is my client configuration: > > > > ConnectionFactoryBuilder factory = new ConnectionFactoryBuilder(); > > > > factory.setProtocol(ConnectionFactoryBuilder.Protocol.BINARY); > > > > SerializingTranscoder t = new SerializingTranscoder(1000000); > > > > t.setCompressionThreshold(1024); > > > > factory.setTranscoder(t); > > > > factory.setOpTimeout(1000); > > > > factory.setTimeoutExceptionThreshold(1998); > > > > factory.setHashAlg(DefaultHashAlgorithm.KETAMA\_HASH); > > > > > > > > factory.setLocatorType(ConnectionFactoryBuilder.Locator.CONSISTENT); > > > > factory.setFailureMode(FailureMode.Redistribute); > > > > factory.setUseNagleAlgorithm(false); -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/ba738dbb-b325-4df1-8f75-47faeafa38a2%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/ba738dbb-b325-4df1-8f75-47faeafa38a2%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 12:58am UTC](https://discuss.elastic.co/t/is-elasticsearch-a-drop-in-replacement-for-memcached/20024/6 "2017-07-06T00:58:38Z")