If slashing latency is the goal, main memory (DRAM) is definitely the place to store data. System architects recognize this, hence the soaring popularity of in-memory database systems (IMDSs).
But DRAM is volatile – some applications need greater durability in the event that someone pulls the plug on the system.
What if DRAM could be made persistent, to “freeze” in-memory data at the moment of system failure? That is the capability delivered by AgigA Tech’s AGIGARAM non-volatile DIMM (NVDIMM), which combines standard DRAM with NAND flash and an ultracapacitor power source. In the first test of its kind, McObject has successfully tested its eXtremeDB IMDS using AgigA Tech's AGIGARAM NVDIMM as main memory storage.
The tests included “pulling the plug” mid-execution, which confirmed the AGIGARAM product’s ability to save data persistently in the event of system failure, and to facilitate recovery. The benchmark tests also showed eXtremeDB’s speed managing data in AgigA Tech’s NVDIMM to be equal to using conventional memory (DRAM). McObject presents the tests results in a free report available here:
To understand the importance of these tests, consider the alternative methods for adding durability to an in-memory database. IMDSs typically support transaction logging, which records (to persistent media) changes to the database and can be used to recover the database after a crash. But this logging adds latency - elimination of which is typically why an IMDS is chosen in the first place!
Another option is to use DRAM backed up by a battery. However, disadvantages of battery-backed RAM include restrictive temperature requirements, leakage risk, limited storage time, long re-charge cycles, finite battery shelf life, and overall high cost-of-ownership.
In contrast, AGIGARAM and eXtremeDB together manage data at DRAM speed, but with persistence and none of the drawbacks of battery-backed RAM. This combination opens the door to a new and powerful approach to database-enabling applications that demand both speed and durability, including mission critical systems for telecom/networking, capital markets, aerospace and industrial control.