WebViewer Server timeouts

Technical Support WebViewer
,
1

WebViewer Version: 10.9
WebViewer Server: 2.2.2

Do you have an issue with a specific file(s)? No
Can you reproduce using one of our samples or online demos? No
Are you using the WebViewer server? Yes
Does the issue only happen on certain browsers? No
Is your issue related to a front-end framework? No
Is your issue related to annotations? No

Please give a brief summary of your issue:

WebViewer Server requests all timeout after server has been online

Please describe your issue and provide steps to reproduce it:

I’ve deployed the WebViewer Server to Google Cloud Run, and upon initial boot up, the server works as expected. However, after an hour or so, all subsequent requests to load documents timeout (currently set to 5 minutes).

We also have uptime checks, which may be keeping the server alive during that time. Do you recommend purposely closing down instances to prevent this sort of error state from happening? What else would cause these sorts of timeouts?

Please provide a link to a minimal sample where the issue is reproducible:

2

Hi there,

Thank you for reaching out to WebViewer forums,

The most common reasons for documents not being displayed is:

  1. Client stickiness not working as intended (this can factor into the websocket being broken)
  2. Websockets not being correctly setup, this really depends on what you’re using in front of WebViewer Server. IE NGINX or HAProxy.
  3. The servers being used are under powered and require more cores, memory, disk speed, or all 3.

Our FAQ has some commonly asked questions

Best regards,
Kevin Kim

3

  1. Is using the load balancer required? I was under the impression that we can use pdftron/webviewer-server by itself.

  2. Do you have any guides or samples you can provide of someone hosting webviewer server on a Cloud Run environment?

  3. I’m not seeing any performance issues on the metrics/utilization side of things. In fact, the CPU and memory utilizations are often under 20%.

I found a more detailed description of the errors, in case it’s more illuminating:

2024-07-02 19:07:16.801 EDT
2024-07-02/23:07:16.802/UTC [pool-5-thread-1] INFO  DocManagement - Kicking off potential fetch of http://0.0.0.0:8090/test/sample.pdf
2024-07-02 19:08:00.803 EDT
2024-07-02/23:08:00.803/UTC [pool-2-thread-2] INFO  ServerConfig - lowQ - 0 - adding job
2024-07-02 19:08:00.803 EDT
2024-07-02/23:08:00.803/UTC [pool-6-thread-1] INFO  CacheManager - Starting CacheManager with limit of 10000MB and max age of 30 minutes
2024-07-02 19:08:01.700 EDT
2024-07-02/23:08:01.701/UTC [pool-2-thread-1] INFO  Monitor - STATUS - Free [3483MB] Total [4096MB] CPU [-100.000000%]
2024-07-02 19:08:01.700 EDT
2024-07-02/23:08:01.701/UTC [pool-2-thread-1] INFO  Monitor - DISK - Free [9223372036GB] Total [9223372036GB]
2024-07-02 19:08:01.700 EDT
2024-07-02/23:08:01.701/UTC [pool-2-thread-1] INFO  Monitor - JAVA MEMORY - Used [62MB] Max [42949MB]
2024-07-02 19:08:02.106 EDT
2024-07-02/23:08:02.107/UTC [pool-6-thread-1] INFO  CacheManager - Skipping cleanup, cache size 14MB below limit of 10000MB
2024-07-02 19:08:02.106 EDT
2024-07-02/23:08:02.107/UTC [pool-6-thread-1] INFO  CacheManager - Exited CacheManager
2024-07-02 19:08:32.704 EDT
2024-07-02/23:08:31.749/UTC [pool-5-thread-1] ERROR DocManagement - Fetch finished with errors: 
2024-07-02 19:08:32.705 EDT
java.net.SocketTimeoutException: Read timed out 	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?] 	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77) ~[?:?] 	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:?] 	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499) ~[?:?] 	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480) ~[?:?] 	at java.base/sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:2079) ~[?:?] 	at java.base/sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:2074) ~[?:?] 	at java.base/java.security.AccessController.doPrivileged(AccessController.java:569) ~[?:?] 	at java.base/sun.net.www.protocol.http.HttpURLConnection.getChainedException(HttpURLConnection.java:2073) ~[?:?] 	at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1631) ~[?:?] 	at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1611) ~[?:?] 	at java.base/java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:529) ~[?:?] 	at com.pdftron.server.DocManagement$DocFetchTask.getSingleFileImpl(DocManagement.java:368) ~[PDFTronSharedServer.jar:?] 	at com.pdftron.server.DocManagement$DocFetchTask.doFetch(DocManagement.java:484) [PDFTronSharedServer.jar:?] 	at com.pdftron.server.DocManagement$DocFetchTask.run(DocManagement.java:184) [PDFTronSharedServer.jar:?] 	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) [?:?] 	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) [?:?] 	at java.base/java.lang.Thread.run(Thread.java:840) [?:?] Caused by: java.net.SocketTimeoutException: Read timed out 	at java.base/sun.nio.ch.NioSocketImpl.timedRead(NioSocketImpl.java:288) ~[?:?] 	at java.base/sun.nio.ch.NioSocketImpl.implRead(NioSocketImpl.java:314) ~[?:?] 	at java.base/sun.nio.ch.NioSocketImpl.read(NioSocketImpl.java:355) ~[?:?] 	at java.base/sun.nio.ch.NioSocketImpl$1.read(NioSocketImpl.java:808) ~[?:?] 	at java.base/java.net.Socket$SocketInputStream.read(Socket.java:966) ~[?:?] 	at java.base/java.io.BufferedInputStream.fill(BufferedInputStream.java:244) ~[?:?] 	at java.base/java.io.BufferedInputStream.read1(BufferedInputStream.java:284) ~[?:?] 	at java.base/java.io.BufferedInputStream.read(BufferedInputStream.java:343) ~[?:?] 	at java.base/sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:826) ~[?:?] 	at java.base/sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:761) ~[?:?] 	at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1710) ~[?:?] 	at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1611) ~[?:?] 	at java.base/java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:529) ~[?:?] 	at com.pdftron.server.DocManagement$DocFetchTask.getSingleFileImpl(DocManagement.java:353) ~[PDFTronSharedServer.jar:?] 	... 5 more
2024-07-02 19:08:32.705 EDT
2024-07-02/23:08:32.708/UTC [http-nio2-0.0.0.0-8090-exec-7] ERROR GetPDF - Failed to GetPDF: 
2024-07-02 19:08:32.705 EDT
java.lang.Exception: unable to complete fetch of http://0.0.0.0:8090/test/sample.pdf
2024-07-02 19:08:32.705 EDT
Read timed out
2024-07-02 19:08:32.705 EDT
	at com.pdftron.server.DocManagement$DocFetchTask.waitForConversion(DocManagement.java:159) ~[PDFTronSharedServer.jar:?]
2024-07-02 19:08:32.705 EDT
	at com.pdftron.server.DocManagement.fetchAndConvert(DocManagement.java:521) ~[PDFTronSharedServer.jar:?]
2024-07-02 19:08:32.705 EDT
	at com.pdftron.server.DocReference.fetchLocalBlocking(DocReference.java:497) ~[PDFTronSharedServer.jar:?]
4

Hi there,

  1. Is using the load balancer required? I was under the impression that we can use pdftron/webviewer-server by itself.

That is correct, you do not need a load balancer but we provide one:
https://hub.docker.com/r/pdftron/wv-loadbalancer

  1. Do you have any guides or samples you can provide of someone hosting webviewer server on a Cloud Run environment?

We have guides on AWS/Azure/DockerHub:

  1. I’m not seeing any performance issues on the metrics/utilization side of things. In fact, the CPU and memory utilizations are often under 20%.

Looking at the server logs:

java.net.SocketTimeoutException: Read timed out 
2024-07-02 19:08:32.705 EDT
2024-07-02/23:08:32.708/UTC [http-nio2-0.0.0.0-8090-exec-7] ERROR GetPDF - Failed to GetPDF: 
2024-07-02 19:08:32.705 EDT
java.lang.Exception: unable to complete fetch of http://0.0.0.0:8090/test/sample.pdf

This can be caused by the server being unable to fetch a file. Wherever you were fetching from at the time may have been experiencing too much traffic or is slow for whatever reason, the default timeout is 20 seconds. This timeout is how long it takes the file server to respond with ‘yes we have this file’ before downloading it.

Best regards,
Kevin Kim

5

Did you see that the file in question was the sample file?
http://0.0.0.0:8090/test/sample.pdf

Does that change your diagnosis of this at all?

6

Hi Zack,

Could you please try confirming if that document url is accessible?

Best regards,
Kevin Kim

7

Intermittently the URL may be down, but it’s unclear why this might be timing out.

Is there any way I can increase the logging or look for other signals as to why these requests are timing out?

8

Hey zack,

You can use getPerfInfo to get your queue latency to determine if a specific work item is causing a block:

Best regards,
Kevin Kim