I'm trying to write a script to test all DataSources of a WebSphere Cell/Node/Cluster. While this is possible from the Admin Console a script is better for certain audiences.
So I found the following article from IBM https://www.ibm.com/support/knowledgecenter/en/SSAW57_8.5.5/com.ibm.websphere.nd.multiplatform.doc/ae/txml_testconnection.html which looks promising as it describles exactly what I need.
After having a basic script like:
ds_ids = AdminConfig.list("DataSource").splitlines()
for ds_id in ds_ids:
AdminControl.testConnection(ds_id)
I experienced some undocumented behavior. Contrary to the article above the testConnection function does not always return a String, but may also throw a exception.
So I simply use a try-catch block:
try:
AdminControl.testConnection(ds_id)
except: # it actually is a com.ibm.ws.scripting.ScriptingException
exc_type, exc_value, exc_traceback = sys.exc_info()
now when I print the exc_value this is what one gets:
com.ibm.ws.scripting.ScriptingException: com.ibm.websphere.management.exception.AdminException: javax.management.MBeanException: Exception thrown in RequiredModelMBean while trying to invoke operation testConnection
Now this error message is always the same no matter what's wrong. I tested authentication errors, missing WebSphere Variables and missing driver classes.
While the Admin Console prints reasonable messages, the script keeps printing the same meaningless message.
The very weird thing is, as long as I don't catch the exception and the script just exits by error, a descriptive error message is shown.
Accessing the Java-Exceptions cause exc_value.getCause() gives None.
I've also had a look at the DataSource MBeans, but as they only exist if the servers are started, I quickly gave up on them.
I hope someone knows how to access the error messages I see when not catching the Exception.
thanks in advance
After all the research and testing AdminControl seems to be nothing more than a convinience facade to some of the commonly used MBeans.
So I tried issuing the Test Connection Service (like in the java example here https://www.ibm.com/support/knowledgecenter/en/SSEQTP_8.5.5/com.ibm.websphere.base.doc/ae/cdat_testcon.html
) directly:
ds_id = AdminConfig.list("DataSource").splitlines()[0]
# other queries may be 'process=server1' or 'process=dmgr'
ds_cfg_helpers = __wat.AdminControl.queryNames("WebSphere:process=nodeagent,type=DataSourceCfgHelper,*").splitlines()
try:
# invoke MBean method directly
warning_cnt = __wat.AdminControl.invoke(ds_cfg_helpers[0], "testConnection", ds_id)
if warning_cnt == "0":
print = "success"
else:
print "%s warning(s)" % warning_cnt
except ScriptingException as exc:
# get to the root of all evil ignoring exception wrappers
exc_cause = exc
while exc_cause.getCause():
exc_cause = exc_cause.getCause()
print exc_cause
This works the way I hoped for. The downside is that the code gets much more complicated if one needs to test DataSources that are defined on all kinds of scopes (Cell/Node/Cluster/Server/Application).
I don't need this so I left it out, but I still hope the example is useful to others too.
Related
I have a script I'm trying to write to process a large amount of data. There are, of course, potential for errors. In the script I need to connect to databases. If the script encounters an error, the code never reaches the point where the connection to the database is terminated. I'd like to have something in my python code that will recognize an error occurs, not matter where, and if nothing else at least close those databases. Does something like this exist? I know I can use try/except, but that would only work if I know exactly where I could get the error? I'm basically looking for a catchall to close my databases in the event an error occurs in a location I didn't anticipate.
To run certain cleanup code even if there is an error, use the finally block:
try:
# do stuff, possible exception
except:
# run this if exception
finally:
# always run this, even if exception
Reference: https://docs.python.org/3/tutorial/errors.html#defining-clean-up-actions
Having:
Velocity template or macro
some object
How to validate the object (#if) and fail (stop further processing) in a way that is easily tracable to the place of failure (like throwing exception in Java).
I am looking for something like this:
#if ( ! $context.treasureMap.containsKey('gold'))
#fail('no golden treasure here')
#end
Background
I am writing a maven site page. The velocity context is injected by maven and contains POM information. I want to test existence of some information from effective pom. When the information is not available, I want to fail.
Requirements
fail Velocity processing > fail site generation > fail maven build.
error message should lead to the place of failure so the site should be fixed
preferably no configuration (no extensions, just constructs/tools contained in plain Velocity)
Tried
Strict Reference Mode
Unwanted configuration, do not want to fail on every occasion.
#evaluate('#end') aka syntax error
(Chose #end as most descriptive to my intent) Basically what I want. Fails the processing and maven build but the error message does not lead back to failure location:
ParseException: Encountered "#end" at line 1, column 1..
You need to make a method call which produce exception.See explanation:
The only place where one could run into trouble within Velocity is if there is a call to a method which throws an exception during runtime. For example, this VTL defines a String $foo and then attempts to call its substring() method on it would throw an IndexOutOfBoundsException:
#set ($foo = "bar")
#set ($bar = $foo.substring(0,10))
When the exception is thrown, the parser will stop processing and throw that exception up the stack tree where it can be caught in the method that caused the parser to execute. At that point, the exception can be handled gracefully.
Using the Java SDK I am creating a load job for just a single record with a fairly complicated schema. When monitoring the status of the load job, it takes a surprisingly long time (but perhaps this is due to working out the schema), but then says:
11:21:06.975 [main] INFO xxx.GoogleBigQuery - Job status (21694ms) create_scans_1384744805079_172221126: DONE
11:24:50.618 [main] ERROR xxx.GoogleBigQuery - Job create_scans_1384744805079_172221126 caused error (invalid) with message
Too many errors encountered. Limit is: 0.
11:24:50.810 [main] ERROR xxx.GoogleBigQuery - {
"message" : "Too many errors encountered. Limit is: 0.",
"reason" : "invalid"
?}
BTW - how do I tell the job that it can have more than zero errors using Java?
This load job does not appear in the list of recent jobs in the console, and as far as I can see, none of the Java objects contains any more details about the actual errors encountered. So how can I pro-grammatically find out what is going wrong? All I can find is:
if (err != null) {
log.error("Job {} caused error ({}) with message\n{}", jobID, err.getReason(), err.getMessage());
try {
log.error(err.toPrettyString());
}
...
In general I am having a difficult time finding good documentation for some of these things and am working it out by trial and error and short snippets of code found on here and older groups. If there is a better source of information than the getting started guides, then I would appreciate any pointers to that information. The Javadoc does not really help and I cannot find any complete examples of loading, querying, testing for errors, cataloging errors and so on.
This job is submitted via a NEWLINE_DELIMITIED_JSON record, supplied to the job via:
InputStream dummy = getClass().getResourceAsStream("/googlebigquery/xxx.record");
final InputStreamContent jsonIn = new InputStreamContent("application/octet-stream", dummy);
createTableJob = bigQuery.jobs().insert(projectId, loadJob, jsonIn).execute();
My authentication and so on seems to work correctly as separate Java code to list the projects, and the datasets in the project all works correctly. So I just need help in working what the actual error is - does it not like the schema (I have records nested within records for instance), or does it think that there is an error in the data I am submitting.
Thanks in advance for any help. The job number cited above is an actual failed load job if that helps any Google staffers who might read this.
It sounds like you have a couple of questions, so I'll try to address them all.
First, the way to get the status of the job that failed is to call jobs().get(jobId), which returns a job object that has an errorResult object that has the error that caused the job to fail (e.g. "too many errors"). The errorStream list is a lost of all of the errors on the job, which should tell you which lines hit errors.
Note if you have the job id, it may be easier to use bq to lookup the job -- you can run bq show <job_id> to get the job error information. If you add the --format=prettyjson it will print out all of the information in the job.
A hint you also might want to consider is to supply your own job id when you create the job -- then even if there is an error starting the job (i.e. the insert() call fails, perhaps due to a network error) you can look up the job to see what actually happened.
To tell BigQuery that some errors are allowed during import, you can use the maxBadResults setting in the load job. See https://developers.google.com/resources/api-libraries/documentation/bigquery/v2/java/latest/com/google/api/services/bigquery/model/JobConfigurationLoad.html#getMaxBadRecords().
The code was run as:
u = subprocess.Popen(['process','abc','def','','ghi','jkl'], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
It doesn't work below due to an error occurred:
ValueError: I/O operation on closed file
I suggest you to try pexpect, it is far more well-suited for this tasks (actually, it is a tool built for these kind of tasks).
You can also browse througn examples and see what its usage looks like.
I'm currently trying to code an add-on the popular game World Of Warcraft for a friend. I don't understand too much about the game myself and debugging it within the game is difficult as he's having to do all the testing.
I'm pretty new to Lua, so this may be a very easy question to answer. But when a Lua error occurs in WoW it throws it on screen and gets in the way, this is very bad to a game player as it will stop their gameplay if it throws the exception at the wrong time. I'm looking for a way to cleanly handle the error being thrown. Here's my code so far for the function.
function GuildShoppingList:gslSlashProc()
-- Actions to be taken when command /gsl is procced.
BankTab = GetCurrentGuildBankTab()
BankInfo = GetGuildBankText(BankTab)
local Tabname, Tabicon, TabisViewable, TabcanDeposit, TabnumWithdrawals, remainingWithdrawals = GetGuildBankTabInfo(BankTab)
p1 = BankInfo:match('%-%- GSL %-%-%s+(.*)%s+%-%- ENDGSL %-%-')
if p1 == nil then
self:Print("GSL could not retrieve information, please open the guild bank and select the info tab allow data collection to be made")
else
self:Print("Returning info for: "..Tabname)
for id,qty in p1:gmatch('(%d+):(%d+)') do
--do something with those keys:
local sName, sLink, iRarity, iLevel, iMinLevel, sType, sSubType, iStackCount = GetItemInfo(id);
local iSum = qty/iStackCount
self:Print("We need "..sLink.." x"..qty.."("..iSum.." stacks of "..iStackCount..")")
end
end
end
The problem being when checking to see if p1 is nil, it still throws a Lua error about trying to call p1 as nil. It will be nil at times and this needs to be handled correctly.
What would be the correct most efficient way to go about this?
You might want to wrap your function in a pcall or xpcall which enables you to intercept any error thrown by Lua.
Aside of that, I personally find this construct easier to read:
p1=string.match(str,pat)
if p1 then
-- p1 is valid, eg not nil or false
else
-- handle the problems
end