This chapter covers how applications interact with replica sets,
How connections and failovers work
Waiting for replication on writes
Routing reads to the correct member
From an applications point of view, a replica set behaves much like
a standalone server. By default, client libraries will connect to the
primary and route all traffic to it. Your application can perform reads
and writes as though it were talking to a standalone server while your
replica set quietly keeps hot standbys ready in the background.
Connections to a replica set are similar to connections to a single
server. Use the MongoClient-equivalent in your
driver and provide a list of seeds for the driver
to connect to. Seeds are members of the replica set. You do not have to
list all members (although you can): when the driver connects to the
seeds, it will discover the other members from them. A connection string
usually looks something like this:
After you’ve had an interview, it’s polite to call or write to the person who interviewed you. Which should you do? How do you decide whether it’s appropriate to write or call?
Suppose the place of employment is small and doesn’t really have much of a business office. When the business isn’t very formal, it’s okay to call. An informal business, for example, might be a car wash, a coffee shop, or a limousine service.
When you call, ask to speak to the person who interviewed you. (Make sure to use the person’s full name.)
Then, thank him or her for the interview and ask if there are any further questions you can answer.
Offer to send along any other information or documents the interviewer may want to consider.
always wise to offer your own telephone number, once again, in case it’s been misplaced.
Suppose you applied at a more formal kind of business—such as a downtown bank, an insurance office, the telephone company, or for a government office. Then it’s best to write a letter to the interviewer. Your letter might look something like this:
The Mafia got its grip on children with the sole purpose of making money. Its leaders were not interested in the spiritual dimension of depravity. But the Illuminati group imposed on the same children its archaic, twisted religious beliefs about extending the rule of their deity, Lucifer. One aspect of these beliefs was that there was a royal bloodline that would birth their rulers. A prophecy had told the Illuminati leaders that my second-born Illuminati child was supposed to rule over our county.
Mother of the heir, 1956
For these Illuminati pregnancies, I had to take up residence away from home. Before I was sent away, I had mind-control sessions to persuade me that I was going to la Madeleine church in Paris, that I was being honored, and that I owed it to Lucifer to obey. They programmed me to believe that I was flying Air France, but instead of driving to the airport, my father switched me to another personality and drove me to a church or monastery in a middle-class section of New York. That's where I would live, with Father Anthony, who dressed like a Vatican priest, and the Brothers. Not until I put this memory together did I realize I had never left New York.
As web developers, we all teeter on the fine line between efficient, timely development and creating code that is universally accessible. I’m sure you’ve heard or used terms like “Mac issue” and “stupid Netscape,” and more seasoned developers will be familiar with the IE “box model hack.” In your early history as a web developer, you’re sure to have written the phrase, “This site is optimized for Internet Explorer
[insert your version here].”
All the “workarounds” you’ve encountered are typically a result of not following the standards set forth by the World Wide Web Consortium (where “an international consortium of Member organizations, a full-time staff, and the public work together to develop Web standards”*).
Following these standards can be tricky, and there are certainly plenty of rules to be followed. As professionals with deadlines and budgets, we are often forced to compromise the right way for the fast way. That’s not to say that writing valid markup is slow, but knowing and following all of the rules is certainly more time-consuming than writing for just one version of one browser.