On Thu, 2015-06-04 at 15:32 -0700, Check Peck wrote: > @Michael: Thanks for your suggestion. Can you explain me why do you think, > it's a TCP issue? I was assuming may be the way I am using RestTemplate in > my code might not be right and that's why it might be resulting in > TIME_WAIT connections a lot on the machine where I have my code deployed > which makes Http Call to my RestService? In the company I am working here, > they have their own Parent POM in which they have spring dependency, the > latest I can get for Spring is 3.2.8: I am not sure whether Spring 3.2.8 > uses new version of HttpClient or not. I did check the first github link > you provided but I was not able to find "ivy.xml" file in 3.2.x branch so > cannot confirm that. May be you know some other way to confirm that. I can > use Spring 3.2.8 version max here. And also, do you see any issues with the > way I am using RestTemplate here, I am just using default way of making > HttpClient calls, may be I need to have some sort of extra parameter to > resolve this issue? Are there anything I need to set while making > RestTemplate calls like "Connection: close" or "keep-alive" anything like > this? And also do you think the way I am using RestTemplate will reuse/pool > my client connections or not? > > @Stefan: I am using RestTemplate in default way as shown in my above code. > I am assuming, it will be reusing/pooling my connections right? I did > google the issue and I found out lot of things, like lowering down the > "tcp_fin_timeout" value from 60 to 30 and some other stuff as mentioned > here in this article: > > http://www.fromdual.com/huge-amount-of-time-wait-connections > > But I was trying to confirm whether it might be related to how I am using > RestTemplate or it is a OS issue? If I can confirm it's an OS issue, then I > will look into that and if let's say the way I am using RestTemplate is not > right, then I might try improving my code to see whether the problem goes > away or not. I am thinking may be the way I am using RestTemplate is not > right? May be I need to have "keep-alive" options on? >
Connections in TIME_WAIT are perfectly normal depending on your OS systems and do not represent an issue with HttpClient resource management. For details see http://wiki.apache.org/HttpComponents/FrequentlyAskedConnectionManagementQuestions Oleg > > On Thu, Jun 4, 2015 at 12:52 PM, Stefan Magnus Landrø < > stefan.lan...@gmail.com> wrote: > > > I presume you are reusing/pooling your client connections, right? > > Also - you could tune your OS to shutdown connections faster. You can > > easily google you issue. > > > > Stefan > > > > 2015-06-04 17:51 GMT+02:00 Check Peck <comptechge...@gmail.com>: > > > > > I am using Spring RestTemplate to make a HTTP Calls to my RestService. I > > am > > > using spring framework 3.1.1 version of RestTemplate. I cannot upgrade > > this > > > since that's what we are using in our company. > > > > > > Now machine which is running my code (which uses RestTemplate) to make > > call > > > to my RestService, I see lot of TIME_WAIT connections opened on that > > > particular machine? > > > > > > - Is there any reason why it happens with RestTemplate or the way I am > > > using it? > > > - Also, what is the connection between TIME_WAIT and HTTP Client calls to > > > my RestService? I am not able to understand this as well. Does HTTP Calls > > > has any significance on TIME_WAIT? There might be some theoretical > > > explanation for this I guess. > > > > > > Below is how I am using RestTemplate in my code base: > > > > > > public class DataClient implements Client { > > > > > > private final RestTemplate restTemplate = new RestTemplate(); > > > private ExecutorService executor = > > > Executors.newFixedThreadPool(10); > > > > > > // for synchronous call > > > @Override > > > public String getSyncData(DataKey key) { > > > String response = null; > > > Future<String> handler = null; > > > try { > > > handler = getAsyncData(key); > > > response = handler.get(key.getTimeout(), > > > TimeUnit.MILLISECONDS); > > > } catch (TimeoutException ex) { > > > // log an exception > > > handler.cancel(true); > > > } catch (Exception ex) { > > > // log an exception > > > } > > > > > > return response; > > > } > > > > > > // for asynchronous call > > > @Override > > > public Future<String> getAsyncData(DataKey key) { > > > Future<String> future = null; > > > > > > try { > > > Task task = new Task(key, restTemplate); > > > future = executor.submit(task); > > > } catch (Exception ex) { > > > // log an exception > > > } > > > > > > return future; > > > } > > > } > > > > > > And below is my simple Task class > > > > > > class Task implements Callable<String> { > > > > > > private final RestTemplate restTemplate; > > > private final DataKey key; > > > > > > public Task(DataKey key, RestTemplate restTemplate) { > > > this.key = key; > > > this.restTemplate = restTemplate; > > > } > > > > > > public String call() throws Exception { > > > ResponseEntity<String> response = null; > > > > > > String url = "some_url_created_by_using_key"; > > > > > > // handling all try catch here > > > response = restTemplate.exchange(url, HttpMethod.GET, null, > > > String.class); > > > > > > return response.getBody(); > > > } > > > } > > > > > > And here is netstat details on my box which is running my code to make > > HTTP > > > Calls to my RestService. I am always seeing very high number of TIME_WAIT > > > connections. > > > > > > 72 ESTABLISHED > > > 2 FIN_WAIT1 > > > 17 LISTEN > > > 3405 TIME_WAIT > > > > > > > > > > > -- > > BEKK Open > > http://open.bekk.no > > > > TesTcl - a unit test framework for iRules > > http://testcl.com > > --------------------------------------------------------------------- To unsubscribe, e-mail: httpclient-users-unsubscr...@hc.apache.org For additional commands, e-mail: httpclient-users-h...@hc.apache.org
