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From Siegfried Goeschl <siegfried.goes...@gmail.com>
Subject Re: Help needed: commons-exec CLOSE_WAIT problem
Date Fri, 05 Feb 2016 17:24:00 GMT
Hi Chris,

according to https://github.com/SeleniumHQ/selenium/pull/1545 the PR is merged and closed
:-)

Cheers,

Siegfried Goeschl

> On 27.01.2016, at 14:52, Siegfried Göschl <siegfried.goeschl@it20one.com> wrote:
> 
> Hi Chris,
> 
> glad to help - please note that I took the freedom to post my findings at https://github.com/SeleniumHQ/selenium/issues/1080
- could you do the same :-)
> 
> Cheers,
> 
> Siegfried Goeschl
> 
> 
> ----- Ursprüngliche Mail -----
> Von: "Chris Gamache" <cgamache@gmail.com>
> An: "Commons Users List" <user@commons.apache.org>
> Gesendet: Mittwoch, 27. Januar 2016 14:43:32
> Betreff: Re: Help needed: commons-exec CLOSE_WAIT problem
> 
> I really appreciate the thorough inspection you have given. With your help
> I think I've targeted the real problem...
> 
> GhostDriver can't exist outside of phantomjs. GhostDriver is an
> implementation of WebDriver Wire Protocol which runs on phantomjs's
> JavaScript engine. It can't run without phantomjs.
> 
> We can rest easy that commons-exec is not holding open the file handle.
> That's good. I think the PhantomJSDriver is firing a copy of phantomjs up
> using commons-exec, but it's not communicating with the service through
> commons-exec. Upon closer inspection selenium-java is communicating through
> tcp/ip to a WebDriver server phantomjs is popping up on random available
> ports. This happens to be an instance of some class that implements
> org.apache.http.client.HttpClient, by default it looks to
> be org.apache.http.impl.client.CloseableHttpClient ... I think that when
> commons-exec terminates phantomjs, thereby terminating the GhostDriver
> server, the HttpClient is still attached to that port.
> 
> Here's my take on the real problem:
> 
> I think the selenium folks didn't consider port closing
> (org.apache.http.client.HttpClient doesn't have a close method to
> implement) a necessary step and they figured that if whatever service the
> HttpClient was attached to shut itself down that the port would
> automatically close itself down also. The standard use for selenium usually
> doesn't require it to run for days and days on end. I can't fault them for
> missing it.
> 
> That being said, they made this difficult to override in consumer classes
> by keeping a lot of the guts of the connections hidden behind private
> classes and private member data.
> 
> So, I'll need to dig into selenium-java, change a few interfaces to make
> sure that whatever HttpClient is used will have a close() hook, and then
> make sure that whatever is driving the HttpClient has access to the close
> hook on shutdown, and fires it. When the HttpClient is closed, the file
> descriptor should disappear.
> 
> Thank you again for your help. It was indispensable!
> 
> CG
> 
> 
> On Tue, Jan 26, 2016 at 4:07 PM, Siegfried Göschl <
> siegfried.goeschl@it20one.com> wrote:
> 
>> Hi Chris,
>> 
>> I played with your GitHub repo [
>> https://github.com/cgamache/openfile](https://github.com/cgamache/openfile)
>> 
>> ### 1. First Take
>> 
>> Your test program actually starts a JVM and the Selenium library start
>> multiple "phantomjs" executable to run the test as shown below
>> 
>> ```
>> application> ps -ef | grep phantom
>> 501  1021   460   0  9:26PM ttys000    0:00.71 java -jar openfile.jar
>> /usr/local/Cellar/phantomjs/2.1.0/bin/phantomjs
>> 501  1073  1062   0  9:26PM ttys000    0:00.08
>> /usr/local/Cellar/phantomjs/2.1.0/bin/phantomjs --webdriver=36418
>> --webdriver-logfile=/Users/sgoeschl/work/github/cgamache/openfile/target/phantomjsdriver.log
>> ```
>> 
>> So commons-exec is used under the hood to run the "phantomjs" binary and
>> make sure nothing hangs (output & error thread pumping, watchdog, ..)
>> 
>> When the "WebDriver" has finished its work there
>> 
>> * is no ***phantomjs*** process running
>> * is only your program running as shown below
>> 
>> ```
>> application> ps -ef | grep phantom
>> 501  1021   460   0  9:23PM ttys000    0:00.72 java -jar openfile.jar
>> /usr/local/Cellar/phantomjs/2.1.0/bin/phantomjs
>> 501  1034   469   0  9:23PM ttys001    0:00.00 grep phantom
>> ```
>> 
>> And as described we have a couple of ports in CLOSE_WAIT stemming from
>> your program
>> 
>> ```
>> application> lsof -p 1021 | grep CLOSE_WAIT
>> java    1021 sgoeschl   16u    IPv6 0x78418468470e25c7       0t0     TCP
>> localhost:50581->localhost:40560 (CLOSE_WAIT)
>> java    1021 sgoeschl   18u    IPv6 0x784184685efd95a7       0t0     TCP
>> localhost:50599->localhost:45319 (CLOSE_WAIT)
>> java    1021 sgoeschl   19u    IPv6 0x784184685efdc0a7       0t0     TCP
>> localhost:50620->localhost:17950 (CLOSE_WAIT)
>> java    1021 sgoeschl   20u    IPv6 0x78418468470e3087       0t0     TCP
>> localhost:50641->localhost:41916 (CLOSE_WAIT)
>> java    1021 sgoeschl   21u    IPv6 0x78418468470e4b67       0t0     TCP
>> localhost:50661->localhost:25113 (CLOSE_WAIT)
>> ```
>> 
>> As far as common-exec is concerned everything is fine - the
>> ***phantomjs*** processes where nicely executed and no process is left
>> 
>> So you have 5 ports in limbo which exactly corresponds to the number of
>> created ***phantom.js*** instances
>> 
>> ```
>> INFO: executable: /usr/local/Cellar/phantomjs/2.1.0/bin/phantomjs
>> INFO: executable: /usr/local/Cellar/phantomjs/2.1.0/bin/phantomjs
>> INFO: executable: /usr/local/Cellar/phantomjs/2.1.0/bin/phantomjs
>> INFO: executable: /usr/local/Cellar/phantomjs/2.1.0/bin/phantomjs
>> INFO: executable: /usr/local/Cellar/phantomjs/2.1.0/bin/phantomjs
>> ```
>> 
>> This nicely corresponds to your test code
>> 
>> ```
>> public static final int REPS = 5;
>> 
>> for (; i < REPS; i++) {
>>   WebDriver driver = new PhantomJSDriver(caps);
>>   driver.get("http://www.apache.org");
>>   driver.quit();
>> }
>> ```
>> 
>> In other words each ***phantomjs*** process leaves exactly on port behind
>> :-)
>> 
>> 
>> ### 2. Second Take
>> 
>> So where is this port coming from? The next session - starting the test
>> programm leaves the 5 ports behind
>> 
>> ```
>> application> lsof -p 1329 | grep CLOSE_WAIT
>> java    1329 sgoeschl   16u    IPv6 0x784184686037bb07       0t0     TCP
>> localhost:51358->localhost:30177 (CLOSE_WAIT)
>> java    1329 sgoeschl   18u    IPv6 0x784184685f5c3b47       0t0     TCP
>> localhost:51379->localhost:cadkey-tablet (CLOSE_WAIT)
>> java    1329 sgoeschl   19u    IPv6 0x784184686037f0c7       0t0     TCP
>> localhost:51400->localhost:43648 (CLOSE_WAIT)
>> java    1329 sgoeschl   20u    IPv6 0x784184686037c5c7       0t0     TCP
>> localhost:51418->localhost:34505 (CLOSE_WAIT)
>> java    1329 sgoeschl   21u    IPv6 0x78418468470e1047       0t0     TCP
>> localhost:51438->localhost:30905 (CLOSE_WAIT)
>> ```
>> 
>> All of ports are actually found in phantomjsdriver.log (cadkey-tablet is
>> actually port 1400)
>> 
>> ```
>> [INFO  - 2016-01-26T20:51:19.697Z] GhostDriver - Main - running on port
>> 30177
>> [INFO  - 2016-01-26T20:51:21.685Z] GhostDriver - Main - running on port
>> 1400
>> [INFO  - 2016-01-26T20:51:23.427Z] GhostDriver - Main - running on port
>> 43648
>> [INFO  - 2016-01-26T20:51:25.156Z] GhostDriver - Main - running on port
>> 34505
>> [INFO  - 2016-01-26T20:51:26.887Z] GhostDriver - Main - running on port
>> 30905
>> ```
>> 
>> So the ports are actually used/opened for ***GhostDriver*** and left there
>> even when ***driver.quit()*** was called
>> 
>> 
>> ### 3. Conclusion
>> 
>> * ASFAIK it is not commons-exec issue since all ***phantomjs*** were
>> cleanly terminated
>> * Each ***PhantomJSDriver*** invocation leaves a port in ***CLOSE_WAIT***
>> behind
>> * Those ports are linked to ***GhostDriver - Main - running on port
>> 30177***
>> 
>> 
>> Cheers,
>> 
>> Siegfried Goeschl
>> 
>> 
>> 
>> ----- Ursprüngliche Mail -----
>> Von: "Chris Gamache" <cgamache@gmail.com>
>> An: "Commons Users List" <user@commons.apache.org>
>> Gesendet: Dienstag, 26. Januar 2016 04:02:41
>> Betreff: Re: Help needed: commons-exec CLOSE_WAIT problem
>> 
>> Most defnintely. This was tested on OSX, but should work properly on Linux
>> also. You'll need to install phantomjs.
>> 
>> You can clone this repo (https://github.com/cgamache/openfile) and build
>> with Maven. The com.codeborne:phantomjsdriver artifact has all of selenium
>> packaged inside.
>> 
>> To run,
>> 
>> $ java -jar openfile.jar /path/to/phantomjs
>> 
>> To examine,
>> 
>> $ lsof -p 38270 | grep CLOSE_WAIT | wc -l
>> 
>> Jan 25, 2016 9:46:17 PM
>> org.openqa.selenium.phantomjs.PhantomJSDriverService <init>
>> 
>> ....... super chatty........
>> 
>> [INFO  - 2016-01-26T02:46:41.169Z] ShutdownReqHand - _handle - About to
>> shutdown
>> 
>> 
>> Sleeping for 30 seconds so you can examine file handles... you should see 5
>> 
>> Then you can use the lsof command at the top of the output, complete with
>> process ID, to check the CLOSE_WAIT file handles.
>> 
>> Thanks for taking a look!
>> 
>> CG
>> 
>> 
>> 
>> On Mon, Jan 25, 2016 at 5:28 PM, Siegfried Göschl <
>> siegfried.goeschl@it20one.com> wrote:
>> 
>>> Hi Chris,
>>> 
>>> there could be couple of reasons for this behaviour - is there a minimal
>>> setup to reproduce the problem?
>>> 
>>> Thanks in advance
>>> 
>>> Siegfried Goeschl
>>> 
>>> ----- Ursprüngliche Mail -----
>>> Von: "Chris Gamache" <cgamache@gmail.com>
>>> An: user@commons.apache.org
>>> Gesendet: Montag, 25. Januar 2016 22:34:34
>>> Betreff: Help needed: commons-exec CLOSE_WAIT problem
>>> 
>>> Hi commons-exec folks,
>>> 
>>> Hoping you can help me figure this out. Selenium Java uses commons-exec
>> 1.3
>>> under the hood to communicate with phantomjs. When it fires up it opens
>> up
>>> a pipe that you can see with lsof:
>>> 
>>> # lsof -p 19947
>>> 
>>> ...
>>> java    19947 user   64     PIPE 0xd2cd00ccca85f9d     16384
>>> ->0xd2cd00ca9fbbf9d
>>> java    19947 user   66     PIPE 0xd2cd00ca31d445d     16384
>>> ->0xd2cd00ca31d4c9d
>>> 
>>> Then we get this in lsof as selenium is driving phantomjs:
>>> 
>>> java    19947 user   62u    IPv6 0xd2cd00cc904879d       0t0      TCP
>>> localhost:49757->localhost:23795 (ESTABLISHED)
>>> 
>>> Then after selenium closes and terminates the executor-- properly, as I
>>> observed by stepping through the code as it executes, but maybe someone
>>> knows otherwise-- we can see in lsof:
>>> 
>>> java    19947 user  62u    IPv6 0xd2cd00cc904879d       0t0      TCP
>>> localhost:49757->localhost:23795 (CLOSE_WAIT)
>>> 
>>> And each successive web driver instance that gets created cause those to
>>> build up and build up and build up until you run out of file handles.
>>> 
>>> ... So are there any considerations for using commons-exec that the
>>> selenium folks might not be addressing during process destruction which
>>> might manifest themselves in these file handles just hanging out, taking
>> up
>>> space? This can't be the correct/uncorrectable behavior.
>>> 
>>> I happen to be using Selenium Java 2.49.1 which is the latest version as
>> of
>>> this moment, and Java 8. It seems like this has been broken for quite
>> some
>>> time though -- https://github.com/SeleniumHQ/selenium/issues/1080
>>> 
>>> Please advise! Thanks!
>>> 
>>> CG
>>> 
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>>> 
>> 
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