Jasper Report Viruatization

Jasper Report Viruatization

There are certain things to care while implementing the Jasper Reports for huge data-set to handle the memory efficiently, so that the application does not go out of memory.

1. Pagination of the data and use of JRDataSource
2. Viruatization of the report.

Problem:-

When there is a huge data set, it is not a good idea to retrieve all the data at one time.The application will hog up the memory and you’re application will go out of memory even before coming to the jasper report engine to fill up the data

Solution :-

To avoid that, the service layer/Db layer should return the data in pages and you gather the data in chunks and return the records in the chunks using JRDataSource interface, when the records are over in the current chunk, get the next chunk until all the chunks gets over


Even after returning the data in chunks, finally the report has to be a single file.Jasper engine build the JasperPrint object for this. To avoid the piling up of memory at this stage, JasperReports provided a really cool feature called Virtualizer

Virtualizer:-

Virtualizer basically serializes and writes the pages into file system to avoid the out of memory condition. There are 3 types of Virtualizer out there as of now

1. JRFileVirtualizer
2. JRSwapFileVirtualizer
3. JRGzipVirtualizer

JRFileVirtualizer:-

JRFileVirtualizer is a really simple virtualizer, where you need to mention the number of pages to keep in memory and the directory in which the Jasper Engine can swap the excess pages into files

Disadvantage with this Virtualizer is file handling overhead. This Virtualizer creates so many files during the process of virtualization and finally produces the required report file from those files.If the dataset is not that large, then you can go far JRFileVirtualizer.

JRSwapFileVirtualizer:-

which overcomes the disadvantage of JRFileVirtualizer. JRSwapFileVirtualizer creates only one swap file,which can be extended based on the size you specify. You have to specify the directory to swap, initial file size in number of blocks and the extension size for the JRSwapFile

Then while creating the JRSwapFileVirtualizer, provide the JRSwapFile as a parameter, and the number of pages to keep in memory. This Virtualizer is the best fit for the huge dataset

JRGzipVirtualizer:-

This Virtualizer is a special virtualizer which does not write the data into files, instead it compresses the jasper print object using the Gzip algorithm and reduces the memory consumption in the heap memory.The Ultimate Guide of JasperReports says that JRGzipVirtualizer can reduce the memory consumption by 1/10th. If you are data-set is not that big for sure and if you want to avoid the file I/O, you can go for JRGzipVirtualizer.

Here I have reused the “virtualizer” sample and added the JRDataSource implementation with paging.
I ran the sample that I have attached here for four scenarios. To tighten the limits to get the real effects, I ran the application with 10 MB as the max heap size (-Xmx10M).

No Virtualizer (heap size 10MB):-

which ended up in out of memory with 10MB max heap size limit while exporting record

[java] Exception in thread “main” java.lang.OutOfMemoryError: Java heap space
[java] Java Result: 1

No Virtualizer (heap size 64MB):-

export2:
[java] null
[java] Filling time : 44547
[java] PDF creation time : 22109
[java] XML creation time : 10157
[java] HTML creation time : 12281
[java] CSV creation time : 2078

With JRFileVirtualizer:-

exportFV:
[java] Filling time : 161170
[java] PDF creation time : 38355
[java] XML creation time : 14483
[java] HTML creation time : 17935
[java] CSV creation time : 5812

With JRSwapFileVirtualizer:-

exportSFV:
[java] Filling time : 51879
[java] PDF creation time : 32501
[java] XML creation time : 14405
[java] HTML creation time : 16579
[java] CSV creation time : 5365

With GZipVirtualizer with lots of GC:-

exportGZV:
[java] Filling time : 84062
[java] Exception in thread “RMI TCP Connection(22)-127.0.0.1″ java.lang.OutOfMemoryError: Java heap space
[java] Exception in thread “RMI TCP Connection(24)-127.0.0.1″ java.lang.OutOfMemoryError: Java heap space
[java] Exception in thread “main” java.lang.OutOfMemoryError: Java heap space
[java] Exception in thread “RMI TCP Connection(25)-127.0.0.1″ java.lang.OutOfMemoryError: Java heap space
[java] Exception in thread “RMI TCP Connection(27)-127.0.0.1″ java.lang.OutOfMemoryError: Java heap space
[java] Java Result: 1

With GZipVirtualizer (max: 13MB):-

exportGZV2:
[java] Filling time : 59297
[java] PDF creation time : 35594
[java] XML creation time : 16969
[java] HTML creation time : 19468
[java] CSV creation time : 10313

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