More on data center management
When you hear the words, “performance bottleneck,” the typical hot spots that come to mind are CPU, Memory, Disk and Network. Those are good places to start looking for bottlenecks but they aren’t the only places performance problems can hide. This list targets six other potential leads for your investigation into the elusive performance breakdown. Sometimes, just knowing where to look might prevent your own personal breakdown.
There is no magic bullet when it comes to finding performance bottlenecks, but knowing where to look for them enhances your aim.
Note that listed items are in no particular order.
The CPU is the brain of the computer where calculations and instruction operations occur.
CPUs can handle millions of calculations and instructions, but performance suffers when the numbers of these operations exceeds capacity. CPUs that sustain greater than 75-percent-busy numbers will slow the entire system. CPUs need some room for activity “bursts” where loads can reach 100 percent for short periods of time. CPU load is a common source of performance bottlenecks.
The rule of thumb on memory is “add more.” When performance problems point to memory, the general consensus to solve the problem, is to add more. This practice is effective only in the short term, however. Performance bottlenecks that point to memory are often the result of poorly designed software (memory leaks) or other system flaws that manifest themselves as memory issues. The key to solving memory performance problems is to find the root cause of the symptom before adding more RAM.
Disk speed, RAID type, storage type and controller technology all combine to produce what’s known as disk I/O. Disk I/O is a common source of performance angst for system administrators and users alike. There are practical and physical limits to performance even when using the best contemporary disk technology. Use best practices when combining and separating workloads on disks. As attractive as leveraged storage is, local disks are still faster than the fastest SAN.
The network is a commonly blamed source of performance bottlenecks, but it is rarely found to be so. Unless there is a network component hardware failure, such as a damaged switch port, bad cable, jabbering network card or router configuration problem, you should look elsewhere for your “network” performance bottleneck. A perceived slowness on the network usually points to one of the list’s other nine entries.
Although no application developer wants to hear it, poorly coded applications masquerade themselves as hardware problems. The fickle finger of guilt points to applications when an otherwise quiescent system suffers greatly when the application is on and shows no signs of difficulty when the application is off. It’s an ongoing battle between system administrators and developers when performance issue occur. Each wants to allege the other’s guilt. A word to the wise after many hundreds of hours of chasing hardware performance bottlenecks: It’s the application.