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In-memory database adds kernel-mode option

Apr 4, 2008 — by Eric Brown — from the LinuxDevices Archive — 13 views

McObject has announced a new kernel-mode version of its ExtremeDB in-memory embedded database. ExtremeDB Kernel Mode (KM) targets any high-performance system that places application logic in the OS kernel, including authentication and firewall software, operating system monitors, and financial arbitrage and… options trading systems.

McObject says that running in kernel mode lets its new product exploit the high priority, zero-latency responsiveness provided to kernel tasks, thus improving sorting, access, and retrieval performance. Another benefit reportedly derives from eliminating the overhead of context-switches between user and kernel mode. However, user-mode applications can still interact with the software using a set of public interfaces implemented via system calls to a kernel-mode proxy, as shown in the diagram below.

ExtremeDB-KM architecture

Other touted features and benefits include:

  • Direct access to data while eliminating the need for buffer management
  • Support for transactions
  • Concurrent access
  • High-level data definition language for embedded systems

eXtremeDB-KM runs on any OS kernel that provides separate user and kernel spaces, supports virtual memory, and provides multitasking, says the company. Specifically supported OSes reportedly include Linux, UNIX, Windows, and several real-time OS (RTOS) distributions.

Database code is rarely placed in the kernel due to fears that tasks such as locking, file and disk I/O, and cache management might overwhelm kernel resources, says McObject. Developers instead either store very limited data management code in kernel space, or more typically, switch to user mode for database tasks.

Stated McObject CEO Steve Graves, “Compared to homegrown code, a proven, off-the-shelf kernel-mode database reduces the likelihood of faults.”


ExtremeDB-KM appears is available now at an undisclosed price.

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