Databases are getting faster every day. But they're still a significant bottleneck for many Web applications or Web sites.
Why? Mechanical hard drives, impeded by the laws of physics, bog down the relational databases that read and write to them.
What are the solutions? Speeding up I/O by reading and writing to a faster solid-state disk rather than a spinning one can help. So can using an in-memory database to cache heavily accessed data in RAM.
Another solution combines a little of both, its backers say, allowing Java-based Web apps and sites to scale their performance while avoiding expensive and possibly less effective database upgrades.
Terracotta's namesake software is an open-source Java clustering solution.
According to CEO Amit Pandey, the software ties multiple Java virtual machines (JVM) underpinning Java-based Web applications into one big cluster. That allows users to add more app servers to scale out at the application level. It caches all of the transactions going through the Java app while writing them to disk separate from the database.
This way, data generated during a transaction can be quickly stored and, if an app server fails, just as quickly recalled, without having to write each intermediate result to the database itself.
That's perfect for data that is vital during a transaction -- say, the items in your shopping cart -- but that does not necessarily need to be written to disk until the transaction (i.e. the purchase) is finished.
Terracotta has about 50 paying customers -- mostly enterprises -- with more than twice that number using it for free, Pandey said. Customers include Adobe Systems, Comcast, JP Morgan and MapQuest.
The largest group of those customers is using Terracotta with Oracle databases. According to Pandey, one company that does online testing was able to double the number of students it served from 10,000 to 20,000 by using Terracotta and adding 10 free open-source application servers. The company spent about US$300,000 on Terracotta and the servers, he said, in contrast to the US$2.1 million price tag the firm was quoted if it added more Oracle databases instead.