Re: Multiple Derby embedded engine instances - problem

2019-07-25 Thread Rick Hillegas

Hi Bob,

It sounds like you need a better inter-process communication technique 
than relying on Derby's database lock file (db.lck). Maybe someone on 
this list can recommend a good resource for you to consult.


Glad to hear that your applications are playing nicely now.

-Rick

On 7/24/19 10:16 PM, Bob M wrote:

Hi Rick

Today I employed a delay in programs 2, 3,4, & 5 on both PCs [5 sec, 10sec,
15sec, & 20sec]

So Program 1 on both machines which uses currency-pair EURCAD start
immediately on the hour and hopefully finishes before 5 secs is up

Then Program 2 on both machines kicks off etc.

So far, I have had no errors involving missing drivers etc.

In addition, I get a new record added to each database each hour

My problem was a timing issue involving instances of derby opening while
another instance was already opened

I don't know how to better my 'work-around'

Bob M




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Re: Multiple Derby embedded engine instances - problem

2019-07-24 Thread Bob M
Hi Rick

Today I employed a delay in programs 2, 3,4, & 5 on both PCs [5 sec, 10sec,
15sec, & 20sec]

So Program 1 on both machines which uses currency-pair EURCAD start
immediately on the hour and hopefully finishes before 5 secs is up

Then Program 2 on both machines kicks off etc.

So far, I have had no errors involving missing drivers etc.

In addition, I get a new record added to each database each hour

My problem was a timing issue involving instances of derby opening while
another instance was already opened

I don't know how to better my 'work-around'

Bob M




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Re: Multiple Derby embedded engine instances - problem

2019-07-24 Thread Rick Hillegas
The missing driver problem is almost certainly a classpath issue. What 
are the classpaths for your applications?


On 7/23/19 7:23 PM, Bob M wrote:

Hi Rick

No - each program references a unique database (i.e. I have 5  different
databases)

My problem seems to be that

1) the first instance of derby is kicked off
2) while it is operating a second instance is kicked off - and it is here
that the execution falters - either not finding a suitable driver or
something else which I can't put my finger on

Here is a clue :-
When I use windows explorer to look at the derby.log it states that the file
has been updated by another program - do I wish to update it - If I say yes
- the details in the log alter - i.e. a different currency-pair coming from
the second program is referenced

Bob M



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Re: Multiple Derby embedded engine instances - problem

2019-07-23 Thread Bob M
Hi Rick

No - each program references a unique database (i.e. I have 5  different
databases)

My problem seems to be that

1) the first instance of derby is kicked off
2) while it is operating a second instance is kicked off - and it is here
that the execution falters - either not finding a suitable driver or
something else which I can't put my finger on

Here is a clue :-
When I use windows explorer to look at the derby.log it states that the file
has been updated by another program - do I wish to update it - If I say yes
- the details in the log alter - i.e. a different currency-pair coming from
the second program is referenced

Bob M



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Re: Multiple Derby embedded engine instances - problem

2019-07-23 Thread Rick Hillegas
I'm not sure what the nature of your problem is. Dual-booting a database 
is a bad idea. See 
http://db.apache.org/derby/docs/10.15/devguide/cdevdvlp20458.html. Are 
multiple programs able to boot the same database simultaneously?


On 7/23/19 4:52 PM, Bob M wrote:

Hi Rick and Bryan

My problem still persists :(

I am trying to access Apache derby more than once at the same time

Is it possible to make more than one copy of derby and uniquely assign each
copy to a different program ?

Alternatively is it possible to add an inhibit which prevents a new task
starting until the previous task is finished?

I can see a need here for a basic scheduler

Any thoughts / suggestions ?

Bob M



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Re: Multiple Derby embedded engine instances - problem

2019-07-23 Thread Bob M
Hi Rick and Bryan

My problem still persists :(

I am trying to access Apache derby more than once at the same time

Is it possible to make more than one copy of derby and uniquely assign each
copy to a different program ?

Alternatively is it possible to add an inhibit which prevents a new task
starting until the previous task is finished?

I can see a need here for a basic scheduler

Any thoughts / suggestions ?

Bob M



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Re: Multiple Derby embedded engine instances - problem

2019-07-14 Thread Bob M
Hi Rick and Bryan

Many, many thanks for all your good advice
Off to a very good start today...
My problem seems to have been a mismatch of derby.jar versions

And now, I know how to setup the derby.properties file and where to put it
:)

Thanks again - a great forum

Bob M
Dunedin
New Zealand



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Re: Multiple Derby embedded engine instances - problem

2019-07-13 Thread Bryan Pendleton
Yes, but not PATH, CLASSPATH. They are different environment variables.

On Fri, Jul 12, 2019 at 9:06 PM Bob M  wrote:
>
> Bryan
>
> Environment Variables
> System Variables
> variable = Path
> value = %DERBY_INSTALL%\lib\derby.jar
>
> Is that what you are meaning?
>
> Bob M
>
>
>
> --
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Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Bob M
Bryan

Environment Variables
System Variables
variable = Path
value = %DERBY_INSTALL%\lib\derby.jar

Is that what you are meaning?

Bob M



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Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Bob M
Hi Rick

I have had a good look around my C drive at "derby" files

I see the latest version of derby I installed was 10.14.2.0
However, the log example I sent you (above) talks about version 10.11.1.0

I also seem to have various length derby.jar files [my bad]

I have now ensured that all copies of derby.jar come from version 10.14.2.0

On Monday I shall see what occurs :)
Bob M
New Zealand



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Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Bryan Pendleton
The EmbeddedDriver is located in the derby.jar jar file, which MUST be
on the CLASSPATH of your program.

bryan

On Fri, Jul 12, 2019 at 3:52 PM Bob M  wrote:
>
> Hi Rick
>
> Ignore the above message... I see I had two 'on the hour' attempts before
> the market closes for the weekend
>
> On the first of these hours (after I added the 2 new properties)
>
> In the logfile I use, I got the following message for each of the 5
> different programs running simultaneously
>
> Unable to load the JDBC driver org.apache.derby.jdbc.Embedded Driver
> Please check your ClASSPATH
>
> and the derby log file was as shown abve
>
> On the second hour
>
> my log file showed only the first line and no derby log file can be found
>
> Bob M
>
>
>
> --
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Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Bob M
Hi Rick

Ignore the above message... I see I had two 'on the hour' attempts before
the market closes for the weekend

On the first of these hours (after I added the 2 new properties)

In the logfile I use, I got the following message for each of the 5
different programs running simultaneously

Unable to load the JDBC driver org.apache.derby.jdbc.Embedded Driver
Please check your ClASSPATH

and the derby log file was as shown abve

On the second hour

my log file showed only the first line and no derby log file can be found

Bob M 



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Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Rick Hillegas
Do you see any errors in derby.log? Can you attach it (after scrubbing 
out any sensitive information)?


On 7/12/19 3:14 PM, Bob M wrote:

Hi Rick

added the two properties as suggested

the result was dramatic !

in each program I write several lines to a file

this file contains only the first of many lines that should have been
outputed - then nothing

what do I do now ?

Bob M



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Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Rick Hillegas
I don't know what that properties object represents. It looks like it is 
configuring the attributes of a Derby connection. What you want to do is 
something else. You want to configure the system properties which are 
used for all embedded Derby databases used by your application. One way 
to do this is to create a file called /derby.properties/ and place that 
file in the current directory of your application. From the attached 
derby.log, it looks like that directory is /C:\Users\64210\JForex/. The 
contents of your /derby.properties/ would be


derby.language.logStatementText=true

derby.stream.error.logSeverityLevel=0


Alternatively, if you boot the application by running the java command 
then you could boot the application like this:


  java -Dderby.language.logStatementText=true 
-Dderby.stream.error.logSeverityLevel=0 ...


Hope this helps,
-Rick

On 7/12/19 8:53 AM, Bob M wrote:

Thanks Rick

I have :-

props.put("user", "xxx");
props.put("password", "");

so do I add a couple of further props.put statements ?

I seem to have just one log file - here is an example where 2 of 5 different
databases are mentioned ???
(I am running 5 different programs at the same time)


Fri Jul 12 00:00:02 UTC 2019:
Booting Derby version The Apache Software Foundation - Apache Derby -
10.11.1.1 - (1616546): instance a816c00e-016b-e37a-c68c-09500118
on database directory C:\Users\\Databases\us_copiosus_NZDUSD_1010 with
class loader com.dukascopy.dds2.greed.agent.a.c@651fbc34
Loaded from http://www.dukascopy.com/JFOREX
java.vendor=Oracle Corporation
java.runtime.version=1.8.0_152-b16
user.dir=C:\Users\64210\JForex
os.name=Windows 10
os.arch=amd64
os.version=10.0
derby.system.home=null
Database Class Loader started - derby.database.classpath=''

Fri Jul 12 00:00:08 UTC 2019: Shutting down Derby engine

Fri Jul 12 00:00:08 UTC 2019:
Shutting down instance a816c00e-016b-e37a-c4d7-0b206fe8 on database
directory C:\Users\b\Databases\us_copiosus_EURCAD_1010 with class loader
com.dukascopy.dds2.greed.agent.a.c@31499e31


Bob M





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Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Bob M
Hi Rick

added the two properties as suggested

the result was dramatic !

in each program I write several lines to a file

this file contains only the first of many lines that should have been
outputed - then nothing

what do I do now ?

Bob M



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Sent from: 
http://apache-database.10148.n7.nabble.com/Apache-Derby-Users-f95095.html


Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Bob M
Thanks Rick

I have :-

props.put("user", "xxx");
props.put("password", "");

so do I add a couple of further props.put statements ?

I seem to have just one log file - here is an example where 2 of 5 different
databases are mentioned ???
(I am running 5 different programs at the same time)


Fri Jul 12 00:00:02 UTC 2019:
Booting Derby version The Apache Software Foundation - Apache Derby -
10.11.1.1 - (1616546): instance a816c00e-016b-e37a-c68c-09500118 
on database directory C:\Users\\Databases\us_copiosus_NZDUSD_1010 with
class loader com.dukascopy.dds2.greed.agent.a.c@651fbc34 
Loaded from http://www.dukascopy.com/JFOREX
java.vendor=Oracle Corporation
java.runtime.version=1.8.0_152-b16
user.dir=C:\Users\64210\JForex
os.name=Windows 10
os.arch=amd64
os.version=10.0
derby.system.home=null
Database Class Loader started - derby.database.classpath=''

Fri Jul 12 00:00:08 UTC 2019: Shutting down Derby engine

Fri Jul 12 00:00:08 UTC 2019:
Shutting down instance a816c00e-016b-e37a-c4d7-0b206fe8 on database
directory C:\Users\b\Databases\us_copiosus_EURCAD_1010 with class loader
com.dukascopy.dds2.greed.agent.a.c@31499e31 


Bob M





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Re: Multiple Derby embedded engine instances - problem

2019-07-12 Thread Rick Hillegas

On 7/11/19 10:15 PM, Bob M wrote:

Hi
I run several java programs at the same time on the same PC - once started
they action on the hour
Each program references a separate sql database - which it hopefully
connects to and updates some records

I have 2 intermitant issues:-

1) "can't find a driver" error on 1 or more of the programs
I have a separate copy of the driver in a different folder for each program

2) an undisclosed error (i.e. no error message) but the connection is NOT
made and nothing is updated

Please can somebody suggest where I might look to sort out these two
problems ?

Bob M



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Each application should have a diagnostic log called derby.log, located 
in the app's current directory. To make sure that the log has maximal 
information, I recommend that you boot the application with the 
following JVM switches:


  -Dderby.language.logStatementText=true 
-Dderby.stream.error.logSeverityLevel=0


Hope this helps,

-Rick