Thank you both for the hints! I didn’t realise I could set connection specific configs in the request context. So that is what I have done now - for each request I just grab the socket, connection and pool timeout from our framework configuration service and apply it on the context before sending the request.
So no need to update the httpclient at all. Simple tweak to code in the end and works as expected. // create the client httpClient = HttpClientFactory.getClient(); // create the context for this thread HttpClientContext httpContext = HttpClientContext.create(); // get timeouts from config httpContext.setRequestConfig(getRequestConfig()); HttpResponse serviceResponse = httpClient.execute(httpRequest, httpContext); Thanks again! Paul. -----Original Message----- From: Oleg Kalnichevski [mailto:ol...@apache.org] Sent: Wednesday, April 25, 2018 11:09 AM To: HttpClient User Discussion <httpclient-users@hc.apache.org> Subject: Re: How to replace / update a httpClient instance? On Wed, 2018-04-25 at 12:48 +0300, Yossi Tamari wrote: > Hi Paul, > > > > Depending on exactly what timeouts you need to change dynamically, > maybe you > can use RequestConfig to set it per request instead of per Client? > > If not, you could override PoolingHttpClientConnectionManager, add a > shutdown flag, and override releaseConnection, so that if this flag > is true, > it will check if there are any other leased connections (using > getTotalStats), and if not it will call shutdown(). Then you can stay > with > your current approach of creating a new Client, but feel safe that > you only > close the previous Client when it is no longer in use. > +1 to that Generally one should only need to modify HttpContext associated with logically related requests, not HttpClient instance used to execute them. Cheers Oleg > > > Yossi. > > > > From: Daly, Paul <paul.d...@dieboldnixdorf.com> > Sent: 25 April 2018 11:12 > To: httpclient-users@hc.apache.org > Subject: How to replace / update a httpClient instance? > > > > Hi All, > > > > > > First time poster, hoping you can provide some advice/help! > > > > > > WE have developed a connector to a back end server using HTTP Client. > The > component with the HTTPClient runs as part of, and is used by, a > larger > application - ie not a standalone application which we have control > to > completely change. As per performance optimisations guide I reuse the > HTTPClient object within this communication component. Its's > initialised on > first use and within the running application, the httpClient object > will be > passed out to multiple threads who each will execute their own > particular > request to the back end. Request objects are reset() by the thread > which > used them. > > > > > > So far so good. All seems to work ok. > > > > However, the application we are running within provides a front end > for > users. For admins, this allows changing of various configuration > items, some > of which are the timeouts for this component. If an admin changes > those > values we want to be able to change the HTTPClient to use the new > values > without a restart of the application. The application framework > provides an > annotation I can use in my class to pick up config change events. I > can > react on that to refresh my timeout values and recreate the client. > > > > This is where my question starts. My solution so far is to simply > replace > the static httpClient with the newly build object which has the new > timeout > values. But this may lead to problems because I am not sure if the > original > object will actually be tidied up by GC once the threads using it > have > closed their connections. > > > > Ideally I would want to explicitly close the original httpClient > before > pointing the static at the new one. However, this means threads which > have > already been handed this httpClient reference will fail (user impact > - not > acceptable). > > > > So I am kind of stuck on how to implement this safely > > > > Ideally I could just change the configured timeouts in the existing > httpClient but I don't see how to do that. > > > > Code snippets are below. > > > > Any ideas / suggestions would be appreciated! > > > > > > > > > > > > /** > > * A HTTP Client to be used by the EIS PH > > */ > > private static CloseableHttpClient httpClient = null; > > > > > > // get client > > public static CloseableHttpClient getClient() { > > > > if (httpClient == null) { > > // create new client > > init(false); > > } > > > > return httpClient; > > } > > > > > > // initialize the client > > private static synchronized void init(boolean forceNewClient) { > > > > if (forceNewClient || (httpClient == null)) { > > > > // get config, timeouts etc from application framework. > > ... > > > > // create the client > > CloseableHttpClient newClient = > HttpClientBuilder.create().useSystemProperties() > > > .setDefaultRequestConfig(config).setMaxConnPerRoute(maxConnectionsPer > Route) > > .setMaxConnTotal(totalMaxConnection).evictExpiredConnect > ions() > > .evictIdleConnections(idleEvictTime, TimeUnit.MINUTES) > > .setConnectionTimeToLive(timeToLive, > TimeUnit.MINUTES).build(); > > > > // set the static member to be the new client now that its built > > httpClient = newClient; > > > > } > > > > > > // listen for application config change events which affect this > component > > @ConfigChangedListener(ConfigurationHelper.OWNER) > > public void onConfigChanged() { > > init(true); > > } > > > > > > Thanks in advance! > > > > Paul. > > > > > > > > > > Paul Daly > > > > Diebold Nixdorf > > 3022 Lake Drive, > > Citywest Business Park, > > Dublin 24, > > Ireland > > Mobile: +353 87 276 4736 > > paul.d...@dieboldnixdorf.com <mailto:paul.d...@dieboldnixdorf.com> > > DieboldNixdorf.com > > > > <https://twitter.com/DieboldNixdorf> > <https://www.facebook.com/DieboldNixdorf> > <https://www.youtube.com/DieboldNixdorf> > <https://www.linkedin.com/company/diebold> > <http://blog.dieboldnixdorf.com/> > > Reg. in England No. 3841833 > > This document and any attachments to it contain information that is > private > and confidential and should only be read by those persons to whom > they are > addressed. 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