The OS is Ubuntu:
$ uname -a
Linux scw-80de9e 4.5.7-std-3 #1 SMP Tue Jul 12 09:56:30 UTC 2016 x86_64
x86_64 x86_64 GNU/Linux
So I ensured that this is called just once, before any HTTP requests:
HttpOp.setDefaultHttpClient(HttpClients.createMinimal());
I'll let you know if the trouble re-appears.
I understand that netstat allows me to list and kill old waiting
connections.
But I wonder whether there is a way to kill from Java such connections
after a timeout .
2017-05-10 15:06 GMT+02:00 Andy Seaborne <[email protected]>:
> It looks like the loadGraph isn't completing, isn't closing the connection
> but also it looks like cases we ave seen where the OS can't release ports
> in the OS fast enough, resulting in lock-ups (usually for localhost). What
> happen is that after 2+ minutes, a few are released, the app make a little
> progress and then stalls again.
>
> What's the OS?
> On Linux: "netstat -t" shows a lot of connections in one of the WAIT
> states.
>
> Could you try with a non-caching HttpClient
>
> one of:
> HttpOp.setDefaultHttpClient(HttpClients.createMinimal());
> and
> HttpOp.setDefaultHttpClient(HttpClients.createDefault());
>
> before any other code that calls out.
>
> Andy
>
>
>
> On 09/05/17 22:47, Jean-Marc Vanel wrote:
>
>> I just call RDFDataMgr.read(),
>> after setting Java timeouts to 5 and 10 seconds.
>>
>> I don't know what you mean by "adjusting the default HTTP client used by
>> Jena" .
>> You mean setting global configuration on Apache HTTP client ?
>>
>> I don't think so, org.apache.http appears just once:
>> import org.apache.http.impl.cookie.DateUtils
>>
>>
>> 2017-05-09 22:41 GMT+02:00 <[email protected]>:
>>
>> Looks possibly like resource contention in the HTTP machinery.
>>>
>>> Are you adjusting the default HTTP client used by Jena?
>>>
>>> ---
>>> A. Soroka
>>>
>>> Jean-Marc Vanel wrote on 5/9/17 10:49 AM:
>>>
>>> In semantic_forms, when user loads an URL, the application tries to load
>>>
>>>> RDF from it, or else it considers the URL as plain foaf:Document and
>>>> allows
>>>> the user to add triples to that URL.
>>>>
>>>> So the application tries to load RDF from an URL with
>>>> RDFDataMgr.loadGraph() ( maybe there is a better way in Jena ? ).
>>>> And, sometimes, in the case of non-RDF content, blocked threads appear,
>>>> and
>>>> retrying in the web application just creates more of these identical
>>>> stacks.
>>>>
>>>> Here is the top of one of the threads obtained by kill -3 :
>>>>
>>>> "application-akka.actor.default-dispatcher-106" #131 prio=5 os_prio=0
>>>> tid=0x00007f0d7c01d000 nid=0x7fde waiting on condition
>>>> [0x00007f0d772f1000]
>>>> java.lang.Thread.State: WAITING (parking)
>>>> at sun.misc.Unsafe.park(Native Method)
>>>> - parking to wait for <0x00000000fef77760> (a
>>>> java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
>>>> at java.util.concurrent.locks.LockSupport.park(LockSupport.java
>>>> :175)
>>>> at
>>>> java.util.concurrent.locks.AbstractQueuedSynchronizer$Condit
>>>> ionObject.await(AbstractQueuedSynchronizer.java:2039)
>>>> at org.apache.http.pool.PoolEntryFuture.await(PoolEntryFuture.
>>>> java:138)
>>>> at
>>>> org.apache.http.pool.AbstractConnPool.getPoolEntryBlocking(A
>>>> bstractConnPool.java:306)
>>>> at
>>>> org.apache.http.pool.AbstractConnPool.access$000(AbstractCon
>>>> nPool.java:64)
>>>> at
>>>> org.apache.http.pool.AbstractConnPool$2.getPoolEntry(
>>>> AbstractConnPool.java:192)
>>>> at
>>>> org.apache.http.pool.AbstractConnPool$2.getPoolEntry(
>>>> AbstractConnPool.java:185)
>>>> at org.apache.http.pool.PoolEntryFuture.get(PoolEntryFuture.
>>>> java:107)
>>>> at
>>>> org.apache.http.impl.conn.PoolingHttpClientConnectionManager
>>>> .leaseConnection(PoolingHttpClientConnectionManager.java:276)
>>>> at
>>>> org.apache.http.impl.conn.PoolingHttpClientConnectionManager
>>>> $1.get(PoolingHttpClientConnectionManager.java:263)
>>>> at
>>>> org.apache.http.impl.execchain.MainClientExec.execute(
>>>> MainClientExec.java:190)
>>>> at
>>>> org.apache.http.impl.client.cache.CachingExec.callBackend(Ca
>>>> chingExec.java:592)
>>>> at
>>>> org.apache.http.impl.client.cache.CachingExec.handleCacheMis
>>>> s(CachingExec.java:356)
>>>> at
>>>> org.apache.http.impl.client.cache.CachingExec.execute(Cachin
>>>> gExec.java:275)
>>>> at
>>>> org.apache.http.impl.execchain.ProtocolExec.execute(
>>>> ProtocolExec.java:184)
>>>> at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.
>>>> java:88)
>>>> at
>>>> org.apache.http.impl.execchain.RedirectExec.execute(
>>>> RedirectExec.java:110)
>>>> at
>>>> org.apache.http.impl.client.InternalHttpClient.doExecute(Int
>>>> ernalHttpClient.java:184)
>>>> at
>>>> org.apache.http.impl.client.CloseableHttpClient.execute(Clos
>>>> eableHttpClient.java:82)
>>>> at
>>>> org.apache.http.impl.client.CloseableHttpClient.execute(Clos
>>>> eableHttpClient.java:55)
>>>> at org.apache.jena.riot.web.HttpOp.exec(HttpOp.java:1054)
>>>> at org.apache.jena.riot.web.HttpOp.execHttpGet(HttpOp.java:281)
>>>> at org.apache.jena.riot.web.HttpOp.execHttpGet(HttpOp.java:316)
>>>> at
>>>> org.apache.jena.riot.system.stream.LocatorHTTP.performOpen(
>>>> LocatorHTTP.java:42)
>>>> at
>>>> org.apache.jena.riot.system.stream.LocatorURL.open(LocatorURL.java:44)
>>>> at
>>>> org.apache.jena.riot.system.stream.StreamManager.openNoMapOr
>>>> Null(StreamManager.java:139)
>>>> at
>>>> org.apache.jena.riot.system.stream.StreamManager.open(Stream
>>>> Manager.java:100)
>>>> at org.apache.jena.riot.RDFDataMgr.open(RDFDataMgr.java:829)
>>>> at org.apache.jena.riot.RDFDataMgr.open(RDFDataMgr.java:819)
>>>> at org.apache.jena.riot.RDFDataMgr.parse(RDFDataMgr.java:664)
>>>> at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:212)
>>>> athttps://rolfpotts.com/lawrence-millman/
>>>> org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:105)
>>>> at org.apache.jena.riot.RDFDataMgr.loadGraph(RDFDataMgr.java:346)
>>>>
>>>> That was obtained by loading https://rolfpotts.com/lawrence-millman/ ,
>>>> a
>>>> pure HTML page.
>>>> There are 6 of these identical stacks.
>>>>
>>>> jena Version = "3.2.0" , using Play! framework 2.5.12 ( with
>>>> netty-server
>>>> under the hood ).
>>>>
>>>> Any idea for fixing this ?
>>>>
>>>>
>>>>
>>
>>
--
Jean-Marc Vanel
http://www.semantic-forms.cc:9111/display?displayuri=http://jmvanel.free.fr/jmv.rdf%23me
Déductions SARL - Consulting, services, training,
Rule-based programming, Semantic Web
+33 (0)6 89 16 29 52
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