I am trying to log the performance counters for my SSIS Pipeline, for things like Buffer memory, Buffers in use, Buffers spooled, etc.
I created a new log and added all those counters to it. Things are beeing logged, at every 15 seconds to the file, but all it's beeing logged are values of 0 - no matter the time of execution or the element beeing counted.
Something is wrong, but I don't know what... and google-ing it, I could find just a couple of people having this problem also, but no actual solution to it.
Any ideea is apreciated.
Thanks!
Have you applied all the latest service packs?
Related
I'm open to posting the code in this section to work through the optimization but its a bit length and complex, so instead I'm hoping that somebody can assist me with a few debugging questions I have. My goal is to find out what is causing my Apex CPU Time Limit Exceeded issue.
When using the Debug Log in its basic or normal layout I receive the message
Maximum CPU Time: 15062 out of 10,000 ** Close to Limit
I've optimized and re-wrote various loops and queries several times now and in each case this number concludes around there which leads me to believe it is lying to me and that my actual usage far exceeds that number. So on my journey I switched the Log Panels of the Developer Console to Analysis in hopes of isolating exactly what loop, method, or area of the code is giving me a headache.
This leads me to my main question and problem.
Execution Tree, Performance Tree & Executed Units
All show me that my durations UNDER the 10,000ms allowance. My largest consumption is 3,556.19ms which is being used by a wrapper class I created and consumed in the constructor method where there is a fair amount of logic that is constructing a fairly complicated wrapper class that spans over 5-7 custom objects. Still even with those 3,000ms the remainder of the process shows at negligible times bringing my total around 4,000ms. Again my question is.... Why am I unable to see or find what is consuming all my time?
Incorrect Iteration Data
In addition to this, on the Performance tree there is a column of data that shows the number of iterations for each method. I know that my Production Org has 81 objects that would essentially call the constructor for my custom wrapper object. I.E. my Constructor SHOULD be called 81 times, but instead it is called 32 times. So my other question is can I rely on the iteration data in the column? Or because it was iterating so many times does it stop counting at a certain point? Its possible that one of my objects is corrupted or causing an infinite loop somehow, but I don't want to dig through all the data in search of that conclusion if its a known issue that the iteration data is not accurate anyway.
System.Debug in the Production org
The Last question is why my System.Debug() lines are not displaying in my Developer Console on the production org. I've added serveral breadcrumbs throughout the code that would help me isolate just which objects are making it through and which are not, however, I cannot in any layout view system.debug messages outside of my Sandbox.
Sorry for the wealth of questions but I did want to give an honest effort to better understand the debugging process in Salesforce. If this is a lost cause I'm happy to start sharing some code as well but hopefully some debugging tips can get me to the solution.
It's likely your debug log got truncated, see "Each debug log must be 20 MB or smaller. If it exceeds this amount, you won’t see everything you need." in https://trailhead.salesforce.com/en/content/learn/modules/apex_basics_dotnet/debugging_diagnostics
Download the log and search for text similar to "skipped 123456 bytes of detailed log" to confirm, some system.debug statements will just not show up.
You might have to fine-tune the log levels (don't log validation rules and workflows? don't log every single variable assignment with "FINE" level etc). You might have to set all flags to NONE, then track only 1 particular class/trigger that you suspect (see https://help.salesforce.com/articleView?id=code_debug_log_classes.htm&type=5 and https://salesforce.stackexchange.com/questions/214380/how-are-we-supposed-to-use-debug-logs-for-a-specific-apex-class-only)
If it's truncated it's possible analysis tools give up (I had mixed luck with console to be honest, sometimes https://apextimeline.herokuapp.com/ is great to give overview - but it'll also fail to parse a 20 MB log...
When all else fails you can load up the log into Notepad++ (or any editor of your choice), find lines related to method entry/method exit (you might need a regular expression search), take these filtered lines tor excel, play with "text to columns" and just look at timing manually, see if there's a record that causes the spike. Because it could be #10 that's the problem, the fact it exhausts limits on #32 of 81 doesn't mean much. Search like [METHOD_ENTRY|METHOD_EXIT]MyTriggerHandler.onBeforeUpdate could be a good start. But first thing is to make sure log is not truncated.
Short question is on the title: I work with my mongo Shell wich is in safe mode by default, and I want to gain better performance by deactivating this behaviour.
Long Question for those willing to know the context:
I am working on a huge set of data like
{
_id:ObjectId("azertyuiopqsdfghjkl"),
stringdate:"2008-03-08 06:36:00"
}
and some other fields and there are about 250M documents like that (whole database with the indexes weights 36Go). I want to convert the date in a real ISODATE field. I searched a bit how I could make an update query like
db.data.update({},{$set:{date:new Date("$stringdate")}},{multi:true})
but did not find how to make this work and resolved myself to make a script that take the documents one after the other and make an update to set a new field which takes the new Date(stringdate) as its value. The query use the _id so the default index is used.
Problem is that it takes a very long time. I already figured out that if only I had inserted empty dates object when I created the database I would now get better performances since there is the problem of data relocation when a new field is added. I also set an index on a relevant field to process the database chunk by chunk. Finally I ran several concurrent mongo clients on both the server and my workstation to ensure that the limitant factor is the database lock availability and not any other factor like cpu or network costs.
I monitored the whole thing with mongotop, mongostats and the web monitoring interfaces which confirmed that write lock is taken 70% of the time. I am a bit disappointed mongodb does not have a more precise granularity on its write lock, why not allowing concurrent write operations on the same collection as long as there is no risk of interference? Now that I think about it I should have sharded the collection on a dozen shards even while staying on the same server, because there would have been individual locks on each shard.
But since I can't do a thing right now to the current database structure, I searched how to improve performance to at least spend 90% of my time writing in mongo (from 70% currently), and I figured out that since I ran my script in the default mongo shell, every time I make an update, there is also a getLastError() which is called afterwards and I don't want it because there is a 99.99% chance of success and even in case of failure I can still make an aggregation request after the end of the big process to retrieve the single exceptions.
I don't think I would gain so much performance by deactivating the getLastError calls, but I think itis worth trying.
I took a look at the documentation and found confirmation of the default behavior, but not the procedure for changing it. Any suggestion?
I work with my mongo Shell wich is in safe mode by default, and I want to gain better performance by deactivating this behaviour.
You can use db.getLastError({w:0}) ( http://docs.mongodb.org/manual/reference/method/db.getLastError/ ) to do what you want but it won't help.
This is because for one:
make a script that take the documents one after the other and make an update to set a new field which takes the new Date(stringdate) as its value.
When using the shell in a non-interactive mode like within a loop it doesn't actually call getLastError(). As such downing your write concern to 0 will do nothing.
I already figured out that if only I had inserted empty dates object when I created the database I would now get better performances since there is the problem of data relocation when a new field is added.
I did tell people when they asked about this stuff to add those fields incase of movement but instead they listened to the guy who said "leave them out! They use space!".
I shouldn't feel smug but I do. That's an unfortunately side effect of being right when you were told you were wrong.
mongostats and the web monitoring interfaces which confirmed that write lock is taken 70% of the time
That's because of all the movement in your documents, kinda hard to fix that.
I am a bit disappointed mongodb does not have a more precise granularity on its write lock
The write lock doesn't actually denote the concurrency of MongoDB, this is another common misconception that stems from the transactional SQL technologies.
Write locks in MongoDB are mutexs for one.
Not only that but there are numerous rules which dictate that operations will subside to queued operations under certain circumstances, one being how many operations waiting, another being whether the data is in RAM or not, and more.
Unfortunately I believe you have got yourself stuck in between a rock and hard place and there is no easy way out. This does happen.
I am a relative beginner at SSIS so I may be doing something silly.
I have a process that involves looping over a heterogenous queue and processing the objects 1 at a time. The process is currently being done in 'set logic' and its dropping stuff. I was asked to rework it in a looping manner, so that decision has been made for me.
I have chosen to implement queue logic in 1 package and the actual processing in another package.
This is all going relatively well considering...
I now have the process up and running, but its slow. 9 seconds per item. Clearly I cant present this solution. :-)
One thing i notice, 1.5 - 2 seconds of each loop are on the ExecutePackage Task in the queue loop.
I cant figure out how to get a hard number, I am using the flashing green box method of performance tuning. The other steps seem to be very fast. Adding indexes, changing sql to sps, all the usual tricks have helped.
Is the UI realiable at all with regards to boxes turning white/yellow/green? Some tasks report times in the progress tab, some dont seem to. So I am counting yellow time.
Should calling a subpackage be that expensive? 1 change i made was I change 'RunInASeparateProcess' to FALSE. I did that because the subpackage produces the following message otherwise:
Error: 0xC0012024 at Script Task: The task "Script Task" cannot run on this edition of Integration Services. It requires a higher level edition.
Task failed: Script Task
The reading i have done seems to advocate multiple packages. Anyone have any counter patterns? Should i stay the course? I started changing to 1 package. Copy/paste doesnt seem to work well w/ SequenceContainers. I would also need to recreate all the variables in the parent package. Doable, but im not sure that is the answer.
Does anyone know of any tuning resources/websites/books they would be willing to share.
Update - I have been tearing things down in an effort to figure out what the problem is. I was thinking it was the package configurations passing variable values. I dont think that is it. I can pass variables to another package w/ nothing in it and it is fast.
I can make the trivial subpackage slow by adding the two connection managers to it.
I suddenly realize I may be making and breaking a connection to both an Oracle Server and a SQL server in both the main package and then the sub package.
Am I correct in this observation?
Is there any way I can reuse the connection between the two packages?
When i google it, most of what i see is suggestions for passing the connection string.
UPDATE - I combined the two packages into one. This performance is not about 1.25 seconds per item, down from about 9. the only thing i can point to that changed is i am now reusing a single connection instead of making multiple connections.
Thanks, I appreciate any help you are kind enough to offer.
Greg
Once you enable logging, I'd suggest running the package from a command window using dtexec. While that doesn't perfectly duplicate the server environment, it does have the advantages of (a) eliminating BIDS as a potential performance issue and (b) being something you can do without jumping through change control hoops.
I'm using Log4Net to write logs to files. Can this serioulsy slow down my application? I know it depends on how much I'm writing away, but let's say that some hundreds of logs can be written per second.
It will slow down your application (obviously) but it depends a lot on your application if the slow down qualifies as "serious". I think you need to let it run and then decide if the performance is acceptable...
Of course it can.
As you already said, it depends on how you write it.
If you are logging to a different hard-drive, things will be better. If you are logging via a message based transport, you will probably be OK.
Yes it can. It is crucial to consider the configuration, so you can configure it to not write that much log and then also not have much overhead.
eg.
if (logger.IsDebugEnabled)
{
logger.DebugFormat("log: {0}", myObject.ToString());
}
This will execute ToString only if needed.
The fact that you need to write the log to the disk when you enabled it - you can't do much against it. But usually it is not useful to write too much log, because nobody will ever read it anyway.
I am not sure regarding the slowness of application.
But i can say that if you are writing hundreds of logs per second and that too into a same file then make sure that thread synchronization is in place because you dont want crashes when multiple threads try to access same file.
"Slow" is not a binary property. It's relative to what else you're doing.
If whatever else you're doing takes 10 times as much wall-clock time as the logging, then logging will increase it by 10 percent: (10/10 + 1/10 = 1.1)
If whatever else you're doing takes 1/9 as much wall-clock time as the logging, then logging will increase it by 10 times: (1/1 + 9/1 = 10)
Does midiOutPrepareHeader, midiInPrepareHeader just setup some data fields, or does it do something that is more time intensive?
I am trying to decide whether to build and destroy the MIDIHDR's as needed, or to maintain a pool of them.
You really have only two ways to tell (without the Windows source):
1) Profile it. Depending on your findings for how long it takes, have a debug-only scoped timer that logs when it suddenly takes longer than what you think is acceptable for your application, or do your pool solution. Though the docs say not to modify the buffer once you call the prepare function, and it seems if you wanted to re-use it you may have to modify it. I'm not familiar enough with the docs to say one way or the other if your proposed solution would work.
2) Step through the assembly and see. Don't be afraid. Get the MSFT public symbols and see if it looks like it's just filling out fields or if it's doing something complicated.