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Ralsina.Me — Roberto Alsina's website

My company has a website now

And you can see it at http://www.net­man­ager­s.­com.ar.

It's span­ish on­ly right now, but that will change in a week or so.

It was an in­ter­est­ing job, be­cause we are us­ing three web apps writ­ten in three dif­fer­ent lan­guages (ph­p/python/per­l) and I want­ed to pro­vide our cus­tomers with a sin­gle lo­gin for all three.

It was a bit of ef­fort, but ed­u­ca­tion­al :-D

On oth­er news, there is now a "Tip­it" link on each post. What's that for? Well, you can use it to give me mon­ey. You get to be list­ed as "guy that gave Rober­to mon­ey", too (as soon as there is one ;-).

Good News: Linux gives life to old hardware. Bad News: Maybe in some cases it shouldn't.

I was in one of my cus­tomer's dat­a­cen­ters the oth­er day, and while I do most work re­mote­ly, I had to take this op­por­tu­ni­ty to take some snap­shots of their proxy serv­er.

This post is just a bit of fun. This is not sup­posed to be their server, it was just a stop­gap mea­sure be­cause of mul­ti­ple hard­ware fail­ures. This is a large, well man­aged com­pa­ny, and this ir­reg­u­lar sit­u­a­tion will be fixed soon. And any­way, it is work­ing just fine.

As you know, Lin­ux can do that kind of job easy with­out much hard­ware re­quire­ments. Af­ter al­l, it has to han­dle at most about 3Mbps of data, and this box has 2GB of ram, so there's plen­ty of room for a speedy cache.

So, let's go for some good news/bad news.

Good news: It's a true-blue IBM Server! Bad news: It's a IBM Netfin­i­ty 5000 (mod­el 3Ry)!

2110.0.Imagen011

Here is some tech in­fo from IBM about it.

Good news: It has 2 CPUs! Bad news: They are two 450Mhz Pen­tium II CPUs.

Good News: it has hot-swap­pable SC­SI disc­s! Bad news: you have no discs for that con­troller, so we will use this 8GB IDE (PATA) disk!

2108.0.Imagen013

And will leave it just sit­ting there by the CD unit, be­sides the huge gap­ing hole in the front where the SC­SI discs would be.

Bad News: it has a ten­dence to over­heat­ing! Good News: You have a place to keep your coffe war­m!

2109.0.Imagen014

Playing with GIT

The guys at http://github.­com have been nice enough to add me to their be­ta pro­gram, so I am do­ing a lit­tle project there, to fig­ure out if I like git or not.

Since ev­ery­one raves about it, I sup­pose I will, and then will have to turn my nu­mer­ous google­code SVN re­pos in­to git mir­rors or what­ev­er the cor­rect ter­mi­nol­o­gy is.

New qmail plugin idea: overload

It should not hap­pen but it does: Your qmail serv­er is over­load­ed. Maybe you are un­der a DOS at­tack, or there is a rea­son why you are get­ting 10x your usu­al amount of mail.

But then you start see­ing how your "not pre­pro­cessed" queue starts grow­ing, and grow­ing...

This can al­so mean things like cla­mav or spa­mas­sas­s­in, which need to check the mail be­fore it gets queued are not keep­ing up with the mail flow, or maybe some IO per­for­ma­ce is­sue.

But what can you do righ now to fix it?

Well, you can dis­able spa­mas­sas­s­in, or, in ex­treme cas­es, shut­down SMTP so the sys­tem has a chance to catch its breath so to speak.

Of course, clos­ing SMTP means your own users can't send email ei­ther, which suck­s.

Now there is a lighter al­ter­na­tive: shut­down SMTP for those who are not your user­s.

Here's the triv­ial code, im­ple­ment­ed as a SPP plug­in, fit to be used in the [mail] sec­tion:

#!/bin/dash

if [ -f /var/qmail/control/overloaded ]
then
      if [ -z "$SMTPAUTHUSER" ]
      then
              echo R451 Temporary Failure: Server overload
              echo overload: $PPID Temporary Failure: Server overload >&2
      fi
fi

And if you are dar­ing and want to make your sys­tem self­-­cor­rect­ing, maybe you should cron some­thing like this:

* * * * * if [ `qmail-qstat  | tail -1 | cut -d: -f2` -gt 100 ];\
then touch /var/qmail/control/overloaded ;\
else rm -f /var/qmail/control/overloaded; fi

I will prob­a­bly code it again in C and make it part of ra/­plu­g­in­s.

Me and the subte.

I moved to Buenos Aires (BA) al­most ex­act­ly 8 years ago. For those who have nev­er been here, let me tell you some things about it. It's large. Do you know Sao Paulo? A bit small­er. Much small­er than Mex­i­co DF. About the same size as New York. Twice the pop­u­la­tion of the Rand­stad. About the same as greater Paris or Is­tan­bul. So fig­ur­ing out a way to move around it was im­por­tan­t.

Vista dos Aires

The way most na­tives do it is by bus. There is a pret­ty ex­ten­sive and ef­fi­cient net­work of bus­es which will take you any­where. There are maybe 150 dif­fer­ent lines, but if you don't know the city, spe­cial­ly the place you are try­ing to reach, they are a recipe for get­ting lost, be­cause you can (will) miss your stop and end any­where else.

Colectivos

To make it worse, I get dizzy on bus­es. The brak­ing and start­ing makes me re­al­ly sick. I can con­trol it, as long as I look out the win­dow, or straight for­ward, and breath re­al­ly care­ful­ly.

So, since I don't drive, and cabs are rel­a­tive­ly ex­pen­sive, I al­ways pre­ferred the sub­way, or, as it is called here, the subte. Plus, on trains and sub­ways I can even read and not get dizzy. I al­ways tried to live close to a sta­tion, I had al­most one hour to read while trav­el­ing and we got along great.

The subte is pret­ty old. The first in Latin Amer­i­ca, and still the on­ly one in a few mil­lion near­by square miles. But it's al­so ... quirky.

For in­stance, I lived in Bel­gra­no, close to the D line. Which had ja­pa­nese cars. How did I know they were ja­pa­nese cars? Well, they had all these things writ­ten on the win­dows in Ja­pa­nese. Sad­ly, I can't find pic­tures of that, and in a re­cent trip I did­n't see them, so it may be that af­ter maybe 20 years some­one de­cid­ed to rub them of­f. That's a pity. I al­ways imag­ined they said in­ter­est­ing stuff, even if they prob­a­bly said "keep your hands in­side the car, you id­iot".

There's al­so the bo­letería-kiosco. A kiosco is a sort of mi­ni drug­store, where you can buy can­dy, a so­da, maybe a com­b, or con­dom­s. A bo­letería is a palce where you buy tick­ets to ride the subte. And in some places, you can do both things. Be­cause they turned the tick­et booths in­to kioscos.

El hombre del Kiosco

Tere is the line at Re­tiro sta­tion, in the C line. There's 4 or 5 bo­leterías. When you get there, of­ten there's 40 or 50 peo­ple in line on the first one. And you can walk just be­side them and buy a tick­et in the 4th or 5th booth, where there's noone wait­ing.

And of course, a clas­sic, the one ev­ery tourist sees. The A line. The orig­i­nal BA sub­te, opened 90 years ago or so... and still us­ing the same cars. Yes, you can ride an­tique, wood­en cars to work on that line. With in­can­des­cent bulbs on glass tulip­s. With man­u­al doors (man­u­al open­ing on­ly, they close au­to­mat­i­cal­ly with bone crush­ing force).

Empty train car

Sure, it's hot. There's no air con­di­tion­ing, and BA can get pret­ty hot in sum­mer. But it's nice in win­ter! It's fast, you can't get lost, and it's just so BA.


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