NTT西日本、個人所有PCの又貸しによる GRID コンピューティングサービスを開始。



[robin] product queue reduced to default 400M

I reduced the size of product queue to default value 400MB. Robin is getting slow and slow. I can't use it any more.

I will watch there is product missing or not.

UML でデータフローを描けるのか





RHEL3 gd 2

GD 2.0.33 is built on RHEL3. I had to remove only gd-devel to install gd, gd-devel, and gd-tools. Only gd-devel! That means I have now two gd packages.
$ rpm -q gd
It's weird, but we have to learn that RPM system allows two packages with the same name to coexist.

RHEL php-devel

mapserver requires php-devel which is not installed on finch (why?). I found an RPM search engine PBONE.NET which has the same version of php. I'd like to install it, but is that really okay?

Bad news: if I want to be really neat, PHP should be rebuilt. That requires imap-devel and unixODBC-devel. Oh no!! Why should I rebuild everything?

sylpheed uninstalled

I've uninstalled sylpheed from finch and robin. Gmail is so confortable that I don't think there is a chance to use sylpheed again.

FireFox super-reload = Control-Shift-R

I'm trying to install srwiki on robin. I had to install rdtool and rttool, rdtool depends on ruby-amstd and racc. I really want to revise srwiki not to depend on those bunch of packages, but it's not current priority.

The largest problem I had is charset. I want to keep default httpd.conf as much as possible. I left default charset ISO-8859-1 (Latin1). That caused text garbled. META HTTP-EQUIV tag doesn't help because the server is sending charset parameter. So I had to add AddDefaultCharset Shift_JIS statement onto .htaccess file.

But it didn't seem to work when I reloaded the page. That was because of stale cache. I had to press Ctrl-Shift-R to overwrite cache (super-reload).

mapserver RPM collection for RHEL3

I did a little for packaging. I wished it is just a rebuild, but the reality is not.
  • netcdf has been installed already.
  • arcsde, proj was rebuilt easily.
  • Rebuild failure for gdal --- libtool installer complains that it is not installing proper path. Does it work if python support is removed?
  • I haven't build, but I learned that mapserver is going to require gd-devel of newer version and php-devel. GD should be replaced and it is supposed to be easy. The problem will be PHP. Should I recompile everything around apache?

htt_server が暴走する

htt_server がこのところ暴走する。日本語入力をしているとマシンが固まることが往々にしてあり、悩ましい限りだ。ロードアベレージを見ると、ログインしているときだけブチ上がっており、笑っちゃう鹿内状態だ。じゃない、笑っちゃうしかない状態だ。なんか漢字変換が固まって放棄したときの状態だけ喜んで学習している気配があるのだがこれ何だ? CPU 負荷 (ロードアベレージ×100) の時系列

how to create table

Let's discuss about how to create table in the initialization scripts. 続きを読む

テーマ:データベース - ジャンル:コンピュータ

how to create database?

What is commonly done when I install a package?

Firstly, a database must be created, unless the package is to share existing one. Some privilege (root password for MySQL) is needed for this. There can be two ways:

  1. The initialization script prompts on terminal to input root password.
  2. Define a standard way to store root password, such as root's ~/.my.cnf file.
I did the latter in previous forex package, but is that right? I believed so, but now I have changed the idea. It is ugly a RPM package depending on a file that is not managed by RPM. And someone might want to stop updating some databases without changing RPM package structure. So my kindest way is:
  1. The initialization script tries to read a common config file.
  2. If non-existent, prompts on terminal, and then save the password to the config file. It shall have mode 0600, owner root:root.

テーマ:データベース - ジャンル:コンピュータ

OGC-WMS 規格を読む (序~6.2.4)

OGC WMS 規格を読んでみることにする。ただし、今回は敵が70ページもあるので、マジメに全文訳出している時間はない。私のノートたらざるを得ない。 続きを読む

So many applications of real-time DB

I'm writing a software package to retrieve and archive weather map information (cf. previous article).

Expecting migration is possible, I always try to RPM package all software I write. In this application, I quickly realized that most of its functionality is similar to that of forex. Those include installation script, uninstallation script, database/table creation, and so on.

I will create similar package even more. In order to minimize the code for maintenance, I will create a common framework to do that. But when? Now or after this project? I guess I should work firstly for the framework.

MySQL と PostgreSQL の共通部分を使うべき

いままで MySQL を使って来たわけだけれど、世の中 PostgreSQL を使っている人も結構居る。で、いつ何時乗り換えを迫られるかわからないので、なるべく日頃から共通部分を勉強しておくようにしなければならない。
  • PostgreSQL には datetime 型にタイムゾーンがつけられるが、MySQL ではつけられない。つまり、DBMS が夏時間のなんたるやを計算してくれることはあてにしてはならないし、時間はなるべく UTC で格納すべきだ。
  • にもかかわらず MySQL には timestamp 型というのがあって、NULL 値を格納しようとすると現在時刻が入る。これは一見便利だがどういうタイムゾーンの時間が入るかという混乱を起こす上に、PostgreSQL ではサポートされていないから使うべきでない。
  • BLOB 型は一応両方でサポートされているみたいだ。SQL 標準万歳。


昨日と関連するけど別の話。私の動かしている MySQL ではいろんなところのデフォルトの文字コードが latin1 とかなっている。で、これを一部のテーブルで変更して utf8 にしたのだけれど、意味なかったかも。

というのは、何が入って来るかわからない文字列は BLOB で格納しているので、所詮文字コードなんか関係ないのだ。 .... ほんとかな? ま、試してみないとわからない。