Is there any way to see how many transaction logs a process (agent_id) currently spans? Or list the transaction logs it's currently using/spanning? I.e. is it possible to check if NUM_LOG_SPAN is about to be reached?
We've had an issue recently whereby a long running transaction breached NUM_LOG_SPAN. This was set to 70, when we had 105 logs. We've increased this now but potentially it may still not be enough. We could set NUM_LOG_SPAN to 0, but that's a last resort... what we'd like to be able to do is at least monitor the situation (and not just wait until it hits and causes issues) - to be able to run a command to see if, for example, a process was now using/spanning, say, 90 of the logs? And then we could decide whether to cancel it or not.
We're after something similar to the following statement where you can see the percentage of transaction log usage:
select log_utilization_percent,dbpartitionnum from sysibmadm.log_utilization
-is there anything similar for monitoring processes to ensure they don't cross the NUM_LOG_SPAN threshold?
NB: This is in a SAP system (NW7.3)... perhaps there's something in DBACOCKPIT to view this too?
As far as I can tell you can't calculate this from the monitor functions only, because none of the monitoring functions expose the Start LSN for a unit of work.
You can do this with db2pd, though. Use db2pd -db <dbname> -logs to find the Current LSN, and use db2pd -db <dbname> -transactions to find Firstlsn for the particular unit of work.
With these two numbers, you can use the formula
(currentLSN - firstLSN)
Logs Files Spanned = -------------------------
logfilsiz * 4096
(You should convert the hex values for current LSN and firstLSN returned by db2pd to decimal values).
Related
My atomist client exposes metrics on commands that are run. Each command is a metric with a username element as well a status element.
I've been scraping this data for months without resetting the counts.
My requirement is to show the number of active users over a time period. i.e 1h, 1d, 7d and 30d in Grafana.
The original query was:
count(count({Username=~".+"}) by (Username))
this is an issue because I dont clear the metrics so its always a count since inception.
I then tried this:
count(max_over_time(help_command{job=“Application
Name”,Username=~“.+“}[1w]) -
max_over_time(help_command{job=“Application name”,Username=~“.+“}[1w]
offset 1w) > 0)
which works but only for one command I have about 50 other commands that need to be added to that count.
I tried the:
"{__name__=~".+_command",job="app name"}[1w] offset 1w"
but this is obviously very expensive (timeout in browser) and has issues with integrating max_over_time which doesn't support it.
Any help, am I using the metric in the wrong way. Is there a better way to query... my only option at the moment is the count (format working above for each command)
Thanks in advance.
To start, I will point out a number of issues with your approach.
First, the Prometheus documentation recommends against using arbitrarily large sets of values for labels (as your usernames are). As you can see (based on your experience with the query timing out) they're not entirely wrong to advise against it.
Second, Prometheus may not be the right tool for analytics (such as active users). Partly due to the above, partly because it is inherently limited by the fact that it samples the metrics (which does not appear to be an issue in your case, but may turn out to be).
Third, you collect separate metrics per command (i.e. help_command, foo_command) instead of a single metric with the command name as label (i.e. command_usage{commmand="help"}, command_usage{commmand="foo"})
To get back to your question though, you don't need the max_over_time, you can simply write your query as:
count by(__name__)(
(
{__name__=~".+_command",job=“Application Name”}
-
{__name__=~".+_command",job=“Application name”} offset 1w
) > 0
)
This only works though because you say that whatever exports the counts never resets them. If this is simply because that exporter never restarted and when it will the counts will drop to zero, then you'd need to use increase instead of minus and you'd run into the exact same performance issues as with max_over_time.
count by(__name__)(
increase({__name__=~".+_command",job=“Application Name”}[1w]) > 0
)
My AEM server after a few days, becomes unresponsive and crashes. As per this article - https://helpx.adobe.com/experience-manager/kb/check-and-analyze-if-JCR-session-leaks-in-your-AEM-instance.html, on checking http://localhost:4502/system/console/jmx I found out that there are more than 60,000 SessionStatistics objects. I would like to know what these represent? Are these active sessions? or is this the list of all the sessions ever created on AEM server?
I would like to know what these represent? Are these active sessions? or is this the list of all the sessions ever created on AEM server?
Yes, these are active open sessions running currently on your AEM server - created since you last started your instance. You can find the last started time from /system/console/vmstat and all the session objects will have a timestamp after the Last Started time. You'll notice the timestamp against the session name. Something similar to this.
"communities-user-admin#session-1132#25/10/2018 5:03:26 PM"
The link you've posted already indicates potential fixes for open sessions.
Another possible reason for Build up of session objects is due to inefficient long running JCR queries (queries without indexes, very broad predicates, etc). This could lead to increase in garbage collection because of increase in memory usage (if mem params are not specified in start script), analysing gc.log might provide some insights. If you know pretty well that queries are causing build up of session objects, you can use these params in your start script to optimize the resources being used.
-Doak.queryLimitInMemory=1000 -Doak.queryLimitReads=1000 -Dupdate.limit=1000 -Doak.fastQuerySize=true
To find location of gc.log, use lsof
lsof -p ${JAVA PID} | grep gc.log
I am looking as the following article:
https://www.ibm.com/support/knowledgecenter/en/SSEPGG_10.1.0/com.ibm.db2.luw.admin.cmd.doc/doc/r0001988.html
I would like to ask about the IMMEDIATE and the DEFERRED part. Sorry I am still confuse and not really understand on it.
in the IMMEDIATE part, it explain that IMMEDIATE is the default, but it requires an instance attachment to be effective. , what does it means that requires an instance attachment to be effective? I though it should be straight take effect after I run the command?
For example:
db2 update dbm cfg using diaglevel 4 immediate
Does this direct take effect on my db2diag log files?
Take care to read the Db2 knowledge-center version that matches your Db2-version. Maybe you are using a more recent version of Db2 like V10.5 or v11.1.
For the DIAGLEVEL parameter, you can change it on the fly i.e. without needing to bounce the Db2-instnce. The new value is effective immediately and you can see this in the db2diag (which will increase quickly in size because of all the extra messages that will appear).
For "instance attachment" it means that you can run db2 attach ... command before running the db2 update dbm cfg ... The details are here.
However, if you are running as the Db2-instance owner and you are on the Db2-server directly (e.g. via ssh etc) then the instance-attachment is not necessary in this specific case. The instance-attachment is necessary when the instance is remote, or is not the current instance, or you are not running as the instance-owner etc.
There is a problem when several users can process the same cube simultaniously and as a result processing of cube fails. So I need to check if certain cube is processing at current moment.
I dont think you can prevent a cube from being processed if someone else is already processing it. What you can do to "help" is run a MDX query to check the last time the cube was processed:
SELECT CUBE_NAME, LAST_DATA_UPDATE FROM $System.MDSCHEMA_CUBES
or check the sys.process table on the realted sql server instance to see if it is running:
select spid, ecid, blocked, cmd, loginame, db_name(dbid) Db, nt_username, net_library, hostname, physical_io,
login_time, last_batch, cpu, status, open_tran, program_name
from master.dbo.sysprocesses
where spid > 50
and loginame <> 'sa'
and program_name like '%Analysis%'
order by physical_io desc
go
use this code to select running processes: (execute this in OLAP)
select *
from $system.discover_Sessions
where session_Status = 1
And this code to cancel running prossesess ! Please change PID to running SESSISONS_SPID
like in example:
<Cancel xmlns ="http://schemas.microsoft.com/analysisservices/2003/engine">
<SPID>92436</SPID>
<CancelAssociated>1</CancelAssociated>
</Cancel<
Probably a better approach to the ones already listed would be to use SQL Server Profiler to watch activity on the Analysis Server. As stated already, the current popular answer has two flaws, the first option only shows the LAST time the cube had been processed. And the second option only shows if something is running. But it doesn't tell you what is running and what if your cube was not processing from a SQL server but a different data source?
Utilizing SQL Server Profiler will tell you not only if something is processing but also details of what is processing. Most of the Events you can filter out. Watch Progress Report Current events if you want real time information... It's usually too much of a fire-hose of data to get real info out of it, but you'll know well that at least a process is going on. Watch Progress Report Begin and End events only to get better information like what is currently being processed, even down to the partition levels. Other events with good information include Command Begin/End and Query Begin/End.
You will see a job running in Task Manager called "MSDARCH" if a cube is processing. Not sure how you can tell which one though.
I am looking for a way to send alerts when a database or log reach 10% space remaining.
Let me preface this question by saying that I intentionally did not include the word "file" in the question. While I have researched this question it appears that most people have their databases set up for auto-growth and then struggle to manage their database(s) at the file system level. There are a ton of examples out there dealing with how to send disk space alerts. THIS IS NOT MY QUESTION! My databases are ALL set to fixed size files. That means files are thus ALL pre-allocated from the file system when they are created or when a database needs to be expanded. As a matter of policy I do not allow ANY database to grow, uncontrolled, to the point of bringing down a whole server at the hands of one badly behaved application. Each database is managed within its pre-alloted space and grown manually as necessary to meet growing demands.
That said I am looking for the best way to send an alert when the database "reaming space" drops below 10% for example - technically I'll probably set up a warning and alert threshold. So far I haven't been able to find anything on this subject since most people seem fixated on disk space which makes this a bit like looking for a needle in a haystack.
I kind of hoped that SQL Server would have simple alert mechanism to do such a simple, obvious, thing right out of the box, but it looks like alerts mostly are designed to catch error messages which is a little late in my book - I'm looking to be a little more proactive.
So, again, looking to send alerts when database "remaining space" drops below various thresholds. Has anyone done this or seen it done?
Thanks!
Yes indeed. I have done this.
It is possible to set counters with queries against system tables. One possibility includes determining the percentage free space in a log or data file. Then, a SQL Alert can be created to E-mail a message to an operator that a particular threshold has been reached on a counter, such as there is only 5% space remaining in a database file. The solution requires several steps, but is possible using existing functionality.
To determine file names and space information, the following query may be used.
SELECT name AS 'File Name' ,
physical_name AS 'Physical Name',
size/128 AS 'Total Size in MB',
size/128.0 - CAST(FILEPROPERTY(name, 'SpaceUsed') AS int)/128.0 AS 'Available Space In MB',
round((CAST(FILEPROPERTY(name, 'SpaceUsed') AS float)/size)* 100 ,2) AS 'Percentage Used',
*
FROM sys.database_files;
Below are steps to set up an alert for percentage space free on a given file.
Create procedure that sets counter with value. This example sets counter number 10.
DECLARE #FreePercent int
SELECT #FreePercent = 100 - round((CAST(FILEPROPERTY(name, 'SpaceUsed') AS float)/size)* 100 ,2)
FROM sys.database_files
WHERE sys.database_files.name = 'NameOfYourLogOrDataFileHere';
EXEC sp_user_counter10 #FreePercent
Create a scheduled job to run the aforementioned procedure
Create SQL agent alert with counter, such that it executes when the free percentage drops below a certain threshold (i.e. 5%)
Configure database mail, test it, and create at least one operator
Enable SQL server agent alert E-mail (properties of agent), and restart the agent