What does the conflict mean in the Nebula Graph of this error edge conflict?
Which process meet this error when this error occurs?
Nebula Graph may return such errors when the Storage service receives multiple requests to insert or update the same vertex or edge within milliseconds. Try the failed requests again later.
Related
Does anyone know what happens when two nodes try to write data at the same time and both initiate the 2PC protocol? Does a request from one node get aborted and another one succeed? The failed node would retry with some exponential backoff?
If not, what happens?
Usually resource managers does not allow both nodes to participate in the same transaction in the same transaction branch at the same time. Probably second node/binary/thread which tries to join to the transaction will get timeout or some other error on xa_start(..., TMJOIN) call.
I am running a query from follower cluster pointing to the table that exists on the leader cluster and get the following error:-
Partial query failure: An unexpected error occurred. (message: 'StorageException with HttpStatusCode 503 was thrown.: : : ', details: 'Source: Kusto::CachedStorageObject')
Since the error seems to be related to cache , I am trying to understand exactly how to interpret it? If something is not found in the follower cache, ADX should have automatically got the data from leader storage right , I don't quite see why it should fail. It's not quite clear what the error means.
Judging by the StorageException with HttpStatusCode 503, this appears to be a transient failure in accessing underlying storage objects.
If the issue persists, I would recommend that you open a support ticket for your resource, via the Azure portal.
I have a Java application using JanusGraph with a DynamoDB backend. Whenever I try to commit a property greater than 1kB, the transaction hangs and never returns, and does not seem to be generating any error messages. How do I fix this? I have tried changing many JanusGraph settings, including storage.buffer-size.
We are trying to create a huge graph (around 100,000 vertices) in titan using gremlin server remote connection. We have followed the example code available at https://github.com/pluradj/titan-tp3-driver-example to create remote connection to titan via gremlin server. We are able to create indices, vertices, edges query the simple graphs created without any problem;
However, when we try to create a huge graph using a generator (it creates vertices and edges directly in the server using remote connection established) , we are getting the following error:
6041316 [gremlin-server-exec-6] WARN org.apache.tinkerpop.gremlin.server.op.AbstractEvalOpProcessor - Exception processing a script on request [RequestMessage{, requestId=81f949ad-0e37-4293-bcaa-0714cb159c3b, op='eval', processor='', args={gremlin=g.V().has('idObj', 'OC97').next().addEdge('OC_LC', g.V().has('idObj', 'LC9643').next()), batchSize=64}}].
java.lang.OutOfMemoryError: GC overhead limit exceeded
at org.codehaus.groovy.reflection.CachedClass$3.initValue(CachedClass.java:106)
at org.codehaus.groovy.reflection.CachedClass$3.initValue(CachedClass.java:84)
at org.codehaus.groovy.util.LazyReference.getLocked(LazyReference.java:49)
at org.codehaus.groovy.util.LazyReference.get(LazyReference.java:36)
at org.codehaus.groovy.reflection.CachedClass.getMethods(CachedClass.java:260)
at groovy.lang.MetaClassImpl.addInterfaceMethods(MetaClassImpl.java:419)
at groovy.lang.MetaClassImpl.fillMethodIndex(MetaClassImpl.java:342)
at groovy.lang.MetaClassImpl.initialize(MetaClassImpl.java:3264)
at org.codehaus.groovy.reflection.ClassInfo.getMetaClassUnderLock(ClassInfo.java:254)
at org.codehaus.groovy.reflection.ClassInfo.getMetaClass(ClassInfo.java:285)
at org.codehaus.groovy.reflection.ClassInfo.getMetaClass(ClassInfo.java:295)
at org.codehaus.groovy.runtime.metaclass.MetaClassRegistryImpl.getMetaClass(MetaClassRegistryImpl.java:261)
at org.codehaus.groovy.runtime.InvokerHelper.getMetaClass(InvokerHelper.java:873)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.createPojoSite(CallSiteArray.java:125)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.createCallSite(CallSiteArray.java:166)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:133)
at Script72559.run(Script72559.groovy:1)
at org.apache.tinkerpop.gremlin.groovy.jsr223.GremlinGroovyScriptEngine.eval(GremlinGroovyScriptEngine.java:534)
at org.apache.tinkerpop.gremlin.groovy.jsr223.GremlinGroovyScriptEngine.eval(GremlinGroovyScriptEngine.java:374)
at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:233)
at org.apache.tinkerpop.gremlin.groovy.engine.ScriptEngines.eval(ScriptEngines.java:102)
at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor.lambda$eval$0(GremlinExecutor.java:258)
at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor$$Lambda$137/1500273035.call(Unknown Source)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
The graph generation is fast in the begining and slows down gradually and fails around 31000 vertices throwing the above error.
We have tried changing the default cache parameters as below
cache.db-cache=true
cache.db-cache-clean-wait=0
cache.db-cache-time=10000
cache.db-cache-size=0.1
Also we have tried deactivating cache by setting cache.db-cache=false. But none of the steps worked for us.
#Our environment:
CDH 5.7.1
Titan 1.1.0-SNAPSHOT
Solr 4.10.3
HBase 1.2.0
Could you please guide us how to overcome this problem?
The problem was forgetting to use Parameterized Scripts http://tinkerpop.apache.org/docs/current/reference/#parameterized-scripts
Gremlin Server caches all scripts that are passed to it: using Parameterized Scripts reduces caching because only not common scripts are cached (g.V(x))
Not using Parameterized Scripts and using instead String.format for example (like we did) implies caching all gremlin scripts separately which is very expensive and causes an OutOfMemoryError
I hope this would help someone ;)
I am trying to use people-API to get second degree data:
Query I am using: https://api.linkedin.com/v1/people/{id}/connections?modified=new.
However, I am getting Access to connections denied error. Is there any way to get 2nd connections data?
No. If it was, we wouldn't return an "Access to connections denied error."