Experts: PHP Time Delay

eob

I have a massive MySQL database that I'm currently writing to HTML. The reasons for this are long so I won't bore you with the details, but there's my problem.

The script, when run, writes about 1400 html files to the servers. That's an incredible server load for shared hosting space, so, I need to insert some kind of time delay where the server writes one file at a time, with say, a 1/4 second time delay between writing files.

How the hell do you get PHP to pause for a set time before continuing on?

i've asked several PHP experts and nobody can come up with an answer?

rehfeld

sleep() and usleep()

rpanning

Links to rehfeld functions: [man]sleep/man and [man]usleep/man

eob

Thanks people,

It certainly works, the only problem I'm having is that it tends to spit a glob of data at the browser (like 20-30 pages) then paused for a good few seconds, then spit out another glob of data. Gives the script a patchy kind of feel, I was hoping for more of a progressive 'one at a time with consistancy' feel like you get with professional DB import scripts for VBulletin,...

Any suggestions on how to improve it?

rpanning

Try doing an [man]ob_flush/man after every line of output or row, whatever. That should send whatever was outputted right to the browser.

eob

Strangely, it doesn't seem to work. What it seems to do (using both ob_flush & usleep) is accumulate a whole bunch of time delays across multiple database pulls, so it basically spits out 30 or so pages, pauses for the sum of the usleeps [ie (usleep(40000))*30] & then do another bunch.

It is reducing the server load and giving more reliable results but it's not exactly eye candy to use.

The end users keep thinking it's a broken script 😃

rpanning

Humm...do you have a test site we can view this at? Also, maybe try [man]ob_start/man before the queries. Ex:

1. ob_start()
2. begining output Ex: <table>
3. connect to DB
    a. run query
    b. print results
    c. ob_flush()
    d. sleep()
4. close DB
5. ending output Ex: </table>
6. ob_end_flush()

Or maybe you can describe what steps you're doing at this point.

Also, try sleeping after every query just for a little bit. Instead of sleeping for a while after so many queries. That way it will output evenly.

tsinka

Hi,

to send the data immediately you need to use flush();

Thomas

Weedpacket

Rather than ob_flush (since we're not doing output buffering here), just try a plain [man]flush[/man].

rehfeld

you could also set a chunk size for output buffering

for example

ob_start(null, 4096);

flushes output every 4096 bytes

that would prob be more efficient than tons of calls to flush()