Hi,

I created a new linode in UK and got into the new hardware with a E5-2670.
I had an IPB board with Debian Squeeze in another provider and just setup every thing like was before, the only deference is worker_processes in nginx that I changed from 4 to 8.

Now my time to first byte it's almost 2x / 3x than before.

Why is this appending? What should I do or where should I start?

Thanks

What was it before? What is it now? What happens if you change worker_processes back to 4?

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/* TODO: need to add signature to posts */

Hi

Before I could see 0,3 to 0,4 and now I have 0,7 to 0,9.
When I change backup to 4 I get the same values.

Check PHP is using APC and that it has enough memory. There is a apc.php that comes with php-apc that will let you see what it's up to.

Check mysql. Mysqltuner is a wonderful tool.

Check your DNS speed with one of the many on-line testers. A good website tester should also tell you about DNS delays.

Check your system isn't doing something really stupid with top or longview.

Hi,

Today TTF is 0,2 and this is the the expected value for the power we have in linode
Could this be related bad neighborhood in my node?

If you changed nothing and your time to first byte went down to a quarter of what it was yesterday then it has to be due to host load. It's outside your control, you can only talk to support.

That, and/or caches have "warmed up."

I was getting about 1500ms or greater FTB values until I migrated from Apache to Nginx utilizing W3TC on WordPress. With W3Tc there's no need to fire up PHP for every page visit and Nginx just serves up the static HTML disk cache files. It brought my FTB values down to around 150ms (that's a huge performance increase!).

http://blog.michaelfmcnamara.com/2012/1 ... x-php-fpm/

The issue here was that TTF had doubled on what should, ostensibly be a faster system.

For what it is worth though, I get decent TTF times out of Wordpress without static file caching or PHP-FPM. APC is essential to that, since otherwise the startup overhead for each request is about 50% the cost of the request processing time.

TTFB is kind of an arbitrary benchmark anyways.

Static file caching really helps with wordpress~~

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me | voltaireMC

What I am seeing is much higher contention for CPU resources on many of the Linodes I already migrated. I think those of us that migrated early have all ended up on the same host machines and are not getting as good performance now because we are all fighting for resources, while before probably on average the load was more spread out on more actual host machines.

I wish I hadn't migrated a bunch of my nodes... they were performing better before because I was getting less CPU steal %!

Side-note: the ones I didn't migrate now have even less CPU contention on them.

It doesn't help that linodes now have 8 virtual cores, not sure what the reasoning behind that decision was. Even though the core count is doubled on the new hosts, it would have probably reduced contention.

Yeah. It sounds more impressive but only on one out of five hosts I migrated am I seeing almost no contention for the CPU. Even though the number of cores on the physical machines is doubled, the ram is I imagine more than doubled, which also means higher density of Linode per physical host. So if I could roll back my migrations to the hosts they were on before, I would, since I'm seeing basically no benefit from the new hosts and I was not bound by RAM anyway. Oh well.

And that's why when I saw the news I thought "I'll wait a few weeks, until they deploy more nextgen hosts."
Just like with almost any other "new, cool service", the initial rush of users ends up overloading things.

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rsk, providing useless advice on the Internet since 2005.

Wise words, rsk, wish I'd listened to my gut and waited as well!