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Not look at some command line options that are related to heap memory on these options or passed the

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July interpreter while writing large programs you could very well encounter situations where you may

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run out of memory and you can get all out of memory errors.

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One reason could be you do creating too many objects on file that we can simply increase the heap size

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.

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But there can also be memory leaks Yes some memory leaks can still be that Angela despite all the hard

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work that GC does.

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We will soon see how memory leak is possible in Java.

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But for now let's see how we can add just a heap size.

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We are command line options.

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Howard in the simple program called GC them all and it declares an end date which is a static variable

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and it has on a million entries.

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OK.

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And each entries and which is basically 4 bytes.

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So if you multiply that so you would get around eight point four megabytes of data.

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So this data structure.

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It's the size of it would be eight point four megabytes.

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So it's going to go ahead and run it.

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But let's go into the run configurations and past the options that we want to pass.

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So let's go into arguments here.

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And so these are your arguments and you would pass the options here.

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So there are some options here which I have already included under do important things that we need

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to note here as x and x and x and x.

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So those are heap related options.

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X is the minimum amount of memory that would be a look at it to heap memory on that is 30 megabytes

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is what I'm passing on.

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X X would be the max.

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Max amount of memory that would be a look at it here.

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And right now it's both of them are 13 and B and if you change it to G here in sort of that would be

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gigabytes on it for display it would be kilobytes of data on print.

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GC dense is basically we want to print the gcd details.

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So it's like GC logging.

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So when our GC happens garbage collection happens it would print all the details of the memory like

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the summary of the memory before GC and after.

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GC OK so the memory the summary of the heap memory and we are forcing the GBM to use serial GCs serial

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collector.

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OK.

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So 39-B is good enough since our data is only 8.4 M-B.

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Now if you run it everything is fine.

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GC did not run yet because there are a sufficient amount of memory and it just did not trigger a GC

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.

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And but still it prints a summary of the heap memory and thats because of the print gcd does that would

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because of that option we have this.

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So its just printing some details about the young Mammootty So this is a memory information and there

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is Edan space from space to space and so on and so to look at it was this much for poor Temby and for

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the older generation.

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I don't mind them BS has been I look at it and there is also the model space.

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I'm using Java 8 so model space.

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So we have metalsmiths to store the metro area to test a class data and we know that it is Bardolph

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actually the need to memory.

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But that information is also getting printed here.

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Now let's just do something go back change the minimum memory to be here.

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So Maxxis does not see a blind run.

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Now you can see this new line here.

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So this is coming because initially GBM hired has only two M-B that's what we specified using the X

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M-S Frank.

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So with that it tried to look at space for this Adeyemi M-B and it free.

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So that's what this says location has value.

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And because of that GC has again iron.

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This is a four year GC cycle.

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So this is the information about this say something about young collection because a full GC would entail

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collection all collection and also metalsmiths collection.

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That's why you see Matt auspice yet at the very end here is for the oil collection.

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OK.

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So initially for the collection for the new generation there was around one maybe and I don't know seven

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sixty eight kilo bytes for all generations.

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So if you sum up it's around to M-B.

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So that's what has been a look at it initially and here it just says that before a young collection

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has been done this is the amount of memory that was used within one generation of 3:45 kilobytes.

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And after DC has been performing it you know it was using 128.

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So something has been freed here.

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And for the same thing for the op ed you're on so 1:46 and it increased OK before collection icles 1:46

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after collection it is 273.

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So maybe most likely something got passed got promoted from the end generation to the older generation

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.

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Unfought Let's see what it is for them or just miss them or just.

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2400 kilobytes before or after so nothing has changed here.

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So that's when we are just.

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Now let's just go back and let's change it.

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Change District 12 maybe and it should still work because we have our data is only eight point four

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on we to LMB.

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But to our surprise it free.

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And the reason for that is because if you see here for the younger generation the space available is

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around 3700 which is less than 8.4 and here eight point one and B has been allocated to older generation

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which is also an eight point four.

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So the thing it failed is because none after Regence had enough space to look at it all put together

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they had more than this but individually they did not have enough space.

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So that was a main reason for this failure on their Ronsard.

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See is happening here.

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So the first you see was just like it tried with two M-B space and it failed.

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Then it increased it to grow let me understand afraid.

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OK.

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So on both of them are full of uses but just that in the second Do you see for some reason it was doing

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it only on the order collection.

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Okay.

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So thats why you have this out-of-memory error on which is we are out of memory you do.

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There is not there isn't enough Jawa space.

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So only is out of this is to increase the heap memory back to 13 and we are maybe more than that but

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there is also one Hokke which we can do.

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And let me just so that we I don't think you would ever do this but what you can do is we can force

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me and disaffiliate here you can force GBM to restrict young generation size to be around 1 and be under-staffed

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it should be a look at it to or generation.

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Now if you do that we are fine.

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It works fine.

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And that's because for the generation that is I don't want M-B on for the old generation now it has

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around 9 M-B.

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So an item be sufficient to horded this.

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Okay.

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So just that's just for a hike.

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Just wanted to show that.

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So that's about it.

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So the main thing is the Exham as on the economics fracs and you might be using it in your professional

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life do.

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And there are many other flaks that we can use for example for model space.

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We can specify the size and there are some flak for that.

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I would try to include some additional pointers and also some additional notes in the resource section

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so you can look up there where our catering group.

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Some other Flack's that we can use.

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Okay.

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So that's the main thing.

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So that's how you can I just heap memory size.

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Okay.

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Thank you.