Is Compression the Solution for Bloated XML in SOA? No
Posted by Sachin Garg on 20th August 2006 | Permanent Link
SOA infrastructure relies heavily on XML to be the default language used for communication, and effective SOA performance management requires efficient ways of handling XML. A close look at the standards stack for SOA shows that XML is the foundation for all the Web Services standards like XML Schema, SOAP, WSDL, and UDDI.
The verbosity of text-based representation by itself also tends to increase the data size in SOA payloads. So XML data representation not only increases data storage and data transfer times in SOA but also increases data parsing times in the context of a SOA, creating a performance challenge for it.
An extreme solution can be to use dedicated XML Hardware, network devices that offload overtaxed servers by processing XML at a higher speed.
Other options include representing XML in a binary format such as Abstract Syntax Notation number One (ASN1).
New Binary XML Standards (XOP, MTOM & RRSHB) are being developed to solve the problem of exchanging large documents between the service provider and the consumer. These schemas address the problem of fitting binary data directly into an XML message.
One obvious solution to solve SOA performance management problems rely on the notion of XML compression. Needless to say, specific application needs are very decisive in choosing a compression technique from the myriad of techniques available.
As XML is mostly text based, something generic like deflate, bzip2 or ppmd can be used. And there are more XML specific options available too, like XMill or XMLPPM which use the nodal structure of XML documents to achieve better compression.
But enough said about compression. This ZDNet blog post puts forward a very refreshing perspective: Can good design overcome the compulsion to simply throw new hardware and systems at a problem?
Popular compression tools are available for those who must deal with the consequences of bad design. In my mind, Binary XML might just distract us from focusing on good design.
Being a data compression enthusiast, I may not be the person from whom you would expect to hear this, but I have to agree with this.
XML compression can be really great to “patch-up” the inefficiencies faced by SOA applications in handling large XML payloads, and fortunately there are solutions available. But nothing beats good design which can eliminate the problem at source.