In short, it is
sometimes cheaper to accept the risk of having to reenter some data than to design a system in which reentry
is never needed.
Network Latency
Because you know you??™re going to lose some amount of data, you decide to have frequent
backups and transfers across the network. However, doing so can actually have the
CHAPTER 6 n MAINTAINING A WARM STANDBY SERVER VIA LOG SHIPPING 146
opposite of the intended effect. If the standby servers are separated by a significant distance,
a large number of small network packets might slow the overall network traffic.
This isn??™t because you don??™t have enough bandwidth, but rather because there are so
many routers and switches in between point A and point B that they become saturated
with processing incoming network packets (the transaction logs). Such saturation is a
rare occurrence, but it??™s an issue many DBAs miss.
BANDWIDTH VS. LATENCY
Bandwidth and latency are two completely different issues, yet many people have a tendency to focus
on bandwidth alone or, worse yet, lump the two into a single category.
Bandwidth is the amount of potential data that can be sent simultaneously.
Pages:
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296