What's the difference between polling and pulling?

Question

What's the difference between polling and pulling (if any)?

Here

Uh, context? I will guess that polling is asking a server every now and then if something of interest has changed. I'd guess that pulling is querying a server and getting a result set back. – Aphonic

The meaning of those words is determined by the context they are used in. In general, they are the same idea. – Seidel

The difference is 0x06, at least in ASCII. EBCDIC may be different :-) – Schafer

@Kevin no, I don't think they're the same. For one thing, think of the direct objects to the two verbs: one "polls" a server, but one only "pulls" a server when you need to move it to another room. – Curd

...And as far as soundex goes, they're the same (P452)! – Aphonic

I could swear this exact question was asked a few days ago – Dulaney

I want to know the prounciation diffference with poll and pull. – Cycad

Answer 1

They're two distinct words. To "poll" is to ask for an answer. To "pull" is to use force to move (actually or conceptually) something towards oneself (again, actually or conceptually).

One "polls" a server when software on a client periodically asks the server for something. One "pulls" data from a database towards client software.

Note that both words have various distinct uses even within the world of computing, but I can't think of any case where they're interchangeable in such a way as to leave meaning unchanged. Low-level device driver code may "poll" an interface to check whether it's ready for some operation, and there's no network traffic involved. In electronics, one "pulls" a signal up or down.

Clients may both "poll" a server and "pull" data from a server, but note that when I use each verb I use different direct objects. It only makes sense to say "pull the server" when you're dragging it across the computer room floor.

Curd

usually client polls server, so your example need clarification – Spite

+1 though I could see "pull the server" as in "pull (from) the server" =) – Squeegee

@Vuntic To "pull the server" would mean that one is moving the server closer to oneself. The meaning is clearly and distinctly different without the preposition "from" interposed. – Curd

hehe =) I know! But it remains that I (and probably a great many people; I'm not that quirky) would probably understand someone who talked about pulling the server as in pulling data from the server. Not that it wouldn't sound a bit weird. – Squeegee

@Vuntic yes, language is a squishy thing, and the meaning of words changes all the time! – Curd

@Curd I think polling requires&includes indirectly pulling data, because you are not polling for the sake of asking, rather you are polling for the sake of pulling the data. Now pulling can be possible or not depending on the availability of the data, like if you pull something it can be pulled or not. – Bramblett

@MosabShaheen I like this definition I think it gives some clarity. A client may poll with the "hopes" of pulling data. But the poll request may result in not pulling data as well. – Penthea

So what is the opposite of poll? It must be what poll is to pull, but for push ... – Isotone

Answer 2

Poll is like when Gallup does a poll of the American people. They are querying for specific information by asking a question.

Pull is like what you do to a rope. You want the rope (or a file, or some data) to be in your location, so you pull it towards you.

Disregardful

Everybody is a comedian - Or as McEnroe would say "You can't be serious", brace yourself and wait for the dings, they will surly come. – Barden

I think this is a serious answer. – Seidel

@Romain: It illustrates the difference pretty clearly. Whattsa matter? Ya don't like examples that are clear and humourous? – Aphonic

Answer 3

There is a possible slight difference.

Polling is attempting to request information at set intervals.

Pulling just refers to the fact that you are requesting data from somebody else rather than having them send it to you.

That being said, I've heard them used interchangeably.

Thallophyte

At some levels they're the same (you're asking something to give you information) and at other levels they're completely different (short status update versus full record sets). Oh, and they're also pronounced very similarly (in English) but you shouldn't let that confuse you into thinking they're that similar. – Aphonic

Answer 4

With respect to network communications, they both refer to the same scheme, where you are periodically requesting data from an external source. See Pull Technology.

Of course the opposite is Pushing, where data is sent as it becomes available.

Homicidal

I would argue that those meanings are really not the same. – Curd

Answer 5

A poll is quick request while a pull is a slow demand.

One may poll asking if information is immediately available which can be pulled. The distinction is not that the answer to a poll must be boolean, but that the answer to a poll is quick and readily available or the answer will be denied. A poll implies that a choice is being offered which is contrary to a pull, where no choice is offered. A pull may cause the caller to wait for the information to become available or may offer other means of returning the detailed information to the caller later when it actually becomes available.

Martellato

Answer 6

For practical use example, I have come across this article (first paragraph) regarding Change Data Capture:

[...] or downstream services and applications poll the source database at fixed intervals to pull the updated data.

Bragi

Answer 7

You are verbatim asking about "polling" vs "pulling", but maybe you are actually asking about "polling" vs "using a pull subscription model".

According to https://dev.to/anubhavitis/push-vs-pull-api-architecture-1djo, they are the same thing:

Pull: Often referred to as polling

Upsilon