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<== Date ==> <== Thread ==>
Subject: Re: cannot read epics archive(d) data with CS-studio
From: astrid morreale via Tech-talk <tech-talk at aps.anl.gov>
To: Michael Davidsaver <mdavidsaver at gmail.com>
Cc: EPICS Tech Talk <tech-talk at aps.anl.gov>
Date: Sun, 16 Aug 2020 10:35:25 -0600
Hi Michael, 
"Any easy way to see if this is a connectivity issue is to put
the URL above into a web browser, or query from the command
line with 'curl'.
I suspect it will work.  "No data found" doesn't seem like
a TCP connection problem, a timeout, or an HTTP error code."

I followed your suggestion but it does not work

Exception report

message Servlet execution threw an exception

description The server encountered an internal error that prevented it from fulfilling this request.

exception 

javax.servlet.ServletException: Servlet execution threw an exception
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

root cause 

java.lang.NoClassDefFoundError: Could not initialize class org.epics.archiverappliance.utils.nio.ArchPaths
	org.epics.archiverappliance.common.BasicContext.<init>(BasicContext.java:25)
	org.epics.archiverappliance.retrieval.DataRetrievalServlet.doGetSinglePV(DataRetrievalServlet.java:436)
	org.epics.archiverappliance.retrieval.DataRetrievalServlet.doGet(DataRetrievalServlet.java:142)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52


I did some digging on the archiver installation and I found a few errors that may give me a hint,
At least I am convinced now that this is an archiver problem and not Cs-studio 
(I am using a pre-existing installation by my experiment and I cannot freely modify things yet otherwise I would have tested myself already a few things):

Catalina error log gives a severe error (for some time it has been there ) with the /retrieval part of the url

Aug 14, 2020 11:38:38 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [DataRetrievalServlet] in context with path [/retrieval] threw exception [Servlet execution threw an exception] with root cause
java.lang.NoClassDefFoundError: Could not initialize class org.epics.archiverappliance.utils.nio.ArchPaths



also I found an inconsistency with the retrieval url definition in the appliance.xml
 <retrieval_url>http://localhost:17668/retrieval/bpl</retrieval_url>
     <data_retrieval_url>http://myspecialurl:17668/retrieval</data_retrieval_url>
the localhost above should be replaced with "myspecialurl" I am not sure what the local computer would be since all should be stored
in myspecialurl. 


Any thoughts? 
and thanks for all your advice.

Astrid


Il giorno sab 15 ago 2020 alle ore 08:42 Michael Davidsaver <mdavidsaver at gmail.com> ha scritto:
On 8/14/20 9:36 PM, astrid morreale wrote:
> Hi Michael, yes thanks a lot for the  hints. 
>
> So I can see the archiver page and I can check that the PV's exist and are being archived.
> I also checked the log messages in Cs studio and it tells me that no data is archived. ...
>
> ie for the PV  BOS it tells me:
>
>
> No data found for PV optimized_800(BOS) + using URL http://myspecialurl:17668/retrieval/data/getData.raw?pv=optimized_800%28BOS%29&from=2020-08-13T11%3A38%3A38.727-05%3A00&to=2020-08-14T11%3A38%3A38.727-05%3A00
>
> so either the retrieval url is somewhere wrong. (it is the same one from the appliances.xml )
> or somewhere a server port is not open?? (I am guessing here)

Any easy way to see if this is a connectivity issue is to put
the URL above into a web browser, or query from the command
line with 'curl'.

I suspect it will work.  "No data found" doesn't seem like
a TCP connection problem, a timeout, or an HTTP error code.

So I would suggest looking more closely at the archiver detailed
status page for the PV in question.  In particular this page
should show the timestamp for the most recent data update stored.
Also some counters of update received, and updates dropped for
various reasons.



> Thanks.
>
>
>
> Il giorno ven 14 ago 2020 alle ore 19:20 Michael Davidsaver <mdavidsaver at gmail.com <mailto:mdavidsaver at gmail.com>> ha scritto:
>
>     On 8/13/20 4:21 PM, astrid morreale via Tech-talk wrote:
>     > Hello everyone,
>     >
>     > I have successfully installed tested my epics->Archiver appl-> cs studio locally
>     > and I have no problems seeing both archived data as well as lived data on my local computer.
>     >
>     > I have tried to reproduce the last step at some remote machine at FNAL for my experiment and I can only see live data.
>     > Some notes for the remote version:
>     >
>     > 1.I did not install the archiver nor epics myself.
>
>     Have you tried the URL you were given in a web browser on
>     the same computer? 
>
>     Are you able to see the archiver status page?  cs-studio may need to
>     be told about any http proxy in between your client machine and the
>     archiver machine.
>
>     If so, can you check the status of the PVs you're trying to retrieve?
>
>     > As I can see the live data it means my pbraw/ data_retrieval_url  structure from the appliances.xml file and feed to the trends should be fine (?)
>
>     Live data comes directly from IOCs (eg. via Channel Access protocol),
>     and not through any archiver.
>
>     > 2. The storage directory remotely is different from what I tested locally.
>     > I installed mine under /home/arch whereas remotely is somewhere else.
>     > This said I checked the remote storage directory and there is lots of data archived.
>     > Could it be that the storage location may be faulting the cs-studio communication with the archiver?
>
>     The storage directories are an internal configuration for the
>     archiver.  Clients never access there directories directly.
>     All data is retrieved through the archiver server (eg. via HTTP).
>
>     > any help hints will be appreciated, Thanks in advance.
>
>     When you run cs-studio, do you see any error messages printed
>     which related to the archiver?  You might have to search
>     for mentions of the archiver URL.
>
>
>
> --
> Astrid Morreale
> Staff Scientist Subatomic Physics Group.  
> Los Alamos National Laboratory.
> astrid at lanl.gov <mailto:astrid at lanl.gov>



--
Astrid Morreale
Staff Scientist Subatomic Physics Group.  
Los Alamos National Laboratory.
astrid at lanl.gov
References:
cannot read epics archive(d) data with CS-studio astrid morreale via Tech-talk
Re: cannot read epics archive(d) data with CS-studio Michael Davidsaver via Tech-talk
Re: cannot read epics archive(d) data with CS-studio astrid morreale via Tech-talk
Re: cannot read epics archive(d) data with CS-studio Michael Davidsaver via Tech-talk
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