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Slow SMTP sessions and SSH logins on your Zimbra server?

By on 28-Feb-2017 in Computers, Sysadmin

When upgrading a Zimbra server to a somewhat recent version (8.7.3 for example), it may attempt to install its own DNS Cache (zimbra-dnscache). It’s obvious that this may cause issues if you are running some other DNS caching service, or your own BIND, on the server. But these are rather obvious issues and not unique to Zimbra.

What is not, however, equally obvious is that you may think that zimbra-dnscache is actually running, and that it is actually doing what it is supposed to be doing.

My first hint that things weren’t as they appeared to be was extremely slow external SMTP sessions when clients like Thunderbird and other “client mailers”, as well as some web based Helpdesk applications were attempting to send e-mail via Zimbra.

The upgrade to Zimbra 8.7.3 had gone quite well, so it wasn’t an obvious place to start looking.

Until I noticed that SSH logins were also quite slow to this server. They had never been slow before. Checking the SSH configuration on the server did not reveal much other than the fact that it was indeed using reverse DNS lookups.

Checking /etc/resolv.conf made everything clear. Zimbra had, in attempt to use its own zimbra-dnscache, added “nameserver 127.0.0.1” to /etc/resolv.conf. In a perfect world, that may have been what I wanted …

After removing 127.0.0.1 from /etc/resolv.conf, inbound SMTP sessions from “client mailers” and web applications went from 7-10 seconds down to 0.5-0.1 seconds. Case closed.

I’m thinking Zimbra should add a post-installation sanity check. When all services are up and running, a DNS lookup to a known host (www.zimbra.com for example) should return within less than a second or two, anything else is an indication that the system may not function as intended.

#zimbra-dnscache

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PHP is_numeric () fails WordPress version string check

By on 16-Jan-2017 in Computers, Development, WordPress

This is, perhaps, obvious to most PHP developers. But it came somewhat as a surprise to me.

Using is_numeric () for validating a WordPress version string, such as ‘4.7’, does not seem to work very well when WordPress introduces minor releases such as ‘4.7.1’.

Since I cannot be bothered to figure out why it behaves in this (erratic, IMHO) way, I have since replaced the call to is_numeric () with a small function using a simple regular expression (regexp):

    function wpVersionStringCheck ($vs)                                                                                                 
    {                                                                                                                                   
        return (preg_match ('/^(\d+\.)+\d+$/', $vs));                                                                                   
    }

I’m sure there is a hole in there somewhere, but on the following strings at least, it gives me the desired result:

1.0 is valid
1.0. is invalid
1.0.1 is valid
1.banana.0 is invalid

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ttf-mscorefonts-installer and Ubuntu 16

By on 13-Jan-2017 in Linux

As has been confirmed in a number of posts on the Internet, there’s a problem with the ttf-mscorefonts-installer package on Ubuntu 16.

There are a number of solutions, and as odd as it might sound, solutions that work for some will fail for others.

I had to mix a number of suggested solutions to get it working on Ubuntu 16.04.LTS. This is what worked for me, your mileage may vary:

sudo rm -rf /var/lib/update-notifier/package-data-downloads/partial/*
sudo dpkg -P ttf-mscorefonts-installer

After which I went to this page to get an updated version of the ttf-mscorefonts-installer:

https://packages.debian.org/en/sid/all/ttf-mscorefonts-installer/download

And from the directory to where you downloaded the .deb file to:

sudo dpkg --install ttf-mscorefonts-installer_3.6_all.deb

Good luck!

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P-Floyd, the awesome Pink Floyd tribute band

By on 19-Nov-2016 in JoHo

What a show, what a performance. I knew P-Floyd was good and certainly wouldn’t put Pink Floyd to shame, but I had not expected this! Wow! I had previously seen Brit Floyd, but I think P-Floyd blew them away. Of course nothing compares to Pink Floyd, but I’m so glad I got to see P-Floyd in action! @ Rival in Stockholm, Sweden on 19 November 2016.

More pictures here: flic.kr/s/aHskQ6ih1P

20161119_1000114 20161119_1000135 20161119_1000173 20161119_1000218

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It’s not a new world today, tomorrow, nor any other day

By on 09-Nov-2016 in JoHo

People are outraged at the outcome of the US Presidential Election 2016, but I’m not quite sure why. Politicians are throwing themselves at the mercy of the Political Correctness lobby and looking for ways to emigrate to some other nation.

I get the fact that you may not like the outcome of a given election, but there mere fact that you are taking part of an election, in a place where one can hope the outcome isn’t rigged, means that you are part of a democracy, even if you think it’s democrazy.

I’m not for a specific candidate of the two offered, but it seems many people have voted for one candidate with the only merit in mind that they dislike the other. The two candidates played their game as best they could, and one of them won.

Trump could never win the election by playing the political game. He’s not a politician. So he shifted the focus to other issues. This is a reasonable tactic in any conflict situation. If you can’t beat your opponent at their game, change the game. Trump made the election be about something completely different than the issues Clinton wanted to raise awareness about. We have seen this in other countries and other elections, and we will continue to see this until “the politicians” get wise and figure out a strategy to highlight the issues they can actually do something about, and possibly win an election with.

Trump is also a very easy media target because of the outbursts. So media attacks him, once again shifting focus from political issues. I’m guessing you can say they took the bait, hook, line, and sinker; and I don’t understand how you on one hand can claim to be a proper journalist, and on the other hand fall for something as obvious as this. It’s called misdirection, smoke and mirrors, or just simply marketing. Cheap tactics, cheap points, and a destructive game? Absolutely. Effective? Very. Mainly thanks to media.

It’s been done before, and it’ll happen again.

Just my two cents, and I’m sure there are about a billion or more other people with different cents, and that’s OK too.

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Bredband2 och avgifter (för att skicka faktura med e-post)

By on 22-Sep-2016 in Computers, JoHo, Swedish

Det här är helt underbart. Bredband2 har lyckats med konststycket att ta 19kr betalt för att skicka ut en faktura, som ett PDF-dokument via e-post. Ursäkta språket, men vad i helvete är det för fel på er, Bredband2? Har ni så dålig infrastruktur och administrativa system så att ni måste ta betalt för att skicka ut e-post?

Är det så här man gör som operatör, när man först tvingar över kunder till e-postfaktura genom att ta betalt för pappersfakturor och därefter börjar ta betalt för e-postfakturor när man inser att ingen längre vill ha pappersfakturor?

Hur dåliga rutiner har ni på företaget Bredband2?

Bredband2 tar betalt för att skicka e-post

Bredband2 tar betalt för att skicka e-post

3

Life free of digital footprints should be a human right

By on 15-Sep-2016 in Computers, JoHo, Web

The feeling that somehow, somewhere, someone connected the dots between your recent live chat session with your online florist and your Facebook account, or Google, or some other service or site that makes billions of dollars on selling your personal Internet usage data. That feeling.

Using a browser plug-in that detects known so-called trackers makes for some rather disturbing revelations. It’s not just about “ad blockers”, or “pop-up blockers”, or disabling support for “third-party cookies”. Many sites stop working cold when you block stuff that has no business being there in the first place.

When your online florist decides to add live chat support to their website they are putting their own business and your integrity at risk. And in many cases they are not even aware of it, nor should they have to be.

So the supplier of the live chat support drops in 10-12 known trackers, including Google, Facebook, Now Interact, and many many more. The live chat function doesn’t work if you have third-party cookies disabled in your browser. In other words, they require you to enable the possibility for sites to indirectly add tracking data to your browser, and you don’t even have to visit those sites.

Your online florist is paying the live chat supplier. The live chat supplier gets money from your florist, from advertisers, and from “web analytics” companies for including a number of trackers in their services. The advertisers and “web analytics” companies then sell advertising slots, perhaps to your online florist (can you say catch-22 ..)

What your online florist may fail to understand is that you as their customer cannot use their live chat support if you block things. So for you, the customer, and your online florist, it’s a lose-lose situation. For the live chat supplier and the advertising and tracking companies, it’s win-win. And a few months down the road, your friends on Facebook will receive suggestions about buying flowers online because you happened to use a live. And the suggested place of purchase will not be your online florist.

The point here is not that it’s impossible to prevent tracking. The point is that many things on the Internet stop working for “common people” if you do attempt to prevent tracking.

(And why would you want to use a live chat function in the first place? Because many companies are so bad at responding to customer support e-mails that you will grow old and senile waiting for a response. By the time it arrives, you won’t remember why you asked the questions in the first place.)

And the biggest problem of all? Nobody seems to care until it’s way too late. And by that time, you will realize that you have been tracked for the past 15-20 years, your children have been tracked since they were born and given their first Gmail account, and so on … maybe your biggest fear should not be giving out your credit card details online or what the NSA knows about your sexual preferences 😉

You may now resume power saving mode … Zzz zzzZzzz 

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Happy Birthday Mom

By on 09-Sep-2016 in JoHo

Happy Birthday Mom, keep on driving them mad up there, I’m doing my best down here <3

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