Tinklaraštis

06/10/2016

Apex 3.2 idle session cleanup and WWV_FLOW_DATA cleanup

Abstract

When users login they get a temporary 'nobody' session with a few populated variables (or many if you have public translations or custom values), after login user gets an assigned session id and starts populating WWV_FLOW_DATA with item values.

Problem

If not maintained WWV_FLOW_DATA explodes and performance degrades.
I suspect that session idle setting is not working in Apex 3.2, tested many settings and checked Apex tables - nothing changes no matter what the settings are. Sessions pile up during the day, default cache purge procedures only allow cleaning up old sessions by date, not by idle period. Thus I can only run it at night or not at all (if environment gets international).

02/02/2016

Oracle Apex internals: template, source, conditional SQL storage

Abstract

While working with Apex I was building, backing up, customizing applications. I also had a few custom themes, theme-rebuilds. Now I need to update interfaces for 22 applications. Update includes custom CSS, JS'es, styles and HTML customizations for regions, region sources, templates, items, buttons. My applications contain hundreds of regions and items, its time to start digging Apex internals. Some of them can be found documented in forums, some of them I was not able to locate.

Warning

Any mistype or abuse may damage Apex IDE, usability, upgradability and your own application sources. Consider yourself warned.

General remarks

01/25/2016

Drupal performance improvement (valid for version 7)

Abstract

Drupal version 7, objective is to improve both Desktop and mobile versions of your website, improve SEO ratings like page loading speed, text to HTML ratio, number of CSS files, Javascript footprint size, overall page footprint size, number of files to load.

Improvement process

Drupal is module based CMS, so you are going to need only a couple of modules added to your installation. Each module and its use follows. Hopefully this article will be updated quite a few times.

PHP filter + Browscap

There are a couple of Drupal modules that allow hiding content based on device size (mobile or desktop). Tried quite a few Mobility modules, but none of them seem to work, where old or required modules like Cache to be turned off. And its not what I wanted.

01/07/2016

Oracle Apex Textarea printing with line breaks

Objective

Use Text Fields or Text Area fields for text input to build a document template generator. Oracle Apex version 4.

Problem(s)

12/09/2015

ImageMagick and ghostscript delegate problem: sh gs command not found

PROBLEM

Recent ImageMagick update kicked a little in the nuts. I mainly convert PDF to PNG and then use them for OCR. Here is how it welcomed me after an update to 6.7.2:

sh: gs: command not found
convert: missing an image filename

11/25/2015

SSL certificate hash transition from SHA1 to SHA2. ORA-28857

Abstract

The SHA-1 cryptographic hash algorithm has been known to be considerably weaker than it was designed to be since at least 2005. As part of their SHA-2 migration plan, Google, Microsoft and Mozilla have announced that they will stop trusting SHA-1 SSL certificates. Google will begin phasing out trust in SHA-1 certificates by the end of 2014, while Microsoft and Mozilla will begin phasing out trust for SHA-1 certificates in 2016.

Problem(s)

10/29/2015

Larry Ellison on self

“When you write a program for Android, you use the Oracle Java tools for everything, and at the very end you push a button and say, ‘Convert this to Android format.'” - Larry Ellison, 2013, CBS interview.

10/29/2015

Oracle 10g on Centos 6.7 - x86 issues: ntcontab.o, snmccolm.o, ORA-27125

Abstract

Its getting harder and harder to install good old 10g on newer Centos versions. Last attempt on 6.5 was semi-problematic, with some extra packages missing, 6.7 deployment was even more challenging.

System specifications

Centos version (/etc/issue): CentOS release 6.7 (Final)
Oracle version: Version 10.2.0.1.0 Production (10201_database_linux_x86_64.cpio)

Problems and solutions

#1: Error invoking target 'ntcontab.o' of makefile

This error occurred around 65% in installation progress, aborting is not an option - more errors will follow and in the end whole process fails. Did some testing and it appears that one process is building the file, next one is instantly deleting it:

10/05/2015

Server monitoring recipe with SNMP: Observium + Nagios

Objective

Everyone having at least couple of servers, even a single server, would want to monitor it eventually. Some time ago I used MRTG for all that, but as the needs expanded I could do less and less with it and in the end it even became too complicated to use. MRTG is powerful, yet vulnerable to simple server restarts - you have to remap your pins.

Recipe

Will jump to it right away: the best option currently is Observium + Nagios. Will tell about the first one in a separate paragraph, it might suffer from an early death some day, but currently its a good tool for the job. I ended up using two tools because Nagios has a very good alerting system, but lacks interfaces and as you probably guessed already Observium has interfaces, but lacks alerting system.

08/29/2015

Gmail attachment cleanup. Cleanup large gmail letters

Even though Gmail gives you quite a lot of storage, for years I have developed a habit to clean up the trash. It just feels right.

Type in "size:20000000" for filtering mails with attachments >20MB. Seach query is in bytes, filter by any size limit you want. "size:5000000" for emails with larger then 5MB attachments.


turinio valdymo sistema (tvs) leidžia patiems redaguoti svetainės turinį, visos funkcijos greitos ir paprastos net mažai įgudusiam vartotojui. pagaminu, sukonfigūruoju, suprojektuoju visą sistemą, užpildau pradiniu turiniu.

modulinė tvs komplektuojama (bet neapsiriboja) iš šių modulių:
- naujienos / blogas
- puslapiai (su ir be komentarų)
- forumas
- automatiniai nuotraukų įrankiai
- krepšelis prekėms (e-parduotuvė)
- seo (standartinis modulis)
- galerijos
- skaidrės
- daugelio kalbų palaikymas
- paypal, paysera (e-parduotuvei)

internetinė aplikacija tai duomenų baze paremta sistema, kurios valdymas atliekamas per naršyklę. tokio tipo aplikacijos nereikalauja jokių papildomų priedų, konfigūracijos, jos yra centralizuotai keičiamos, taisomos, atnaujinamos. mūsų kuriamų aplikacijų pagrindas yra oracle duomenų bazė, ko pasekoje mes galima pasiūlyti galingas, lanksčias, norimo sudėtingumo lygio aplikacijas.

internetinė aplikacijos gali būti pritaikomos šiems sprendimams:
- apskaitos įrankiai (finansų, laiko, prekių, formos)
- internetinė parduotuvė
- interneto portalas
- duomenų surinkimo terminalas

parduotuvės galimybės:
- prekių katalogas
- sandėlis (prekių kiekių apskaita)
- užsakymų valdymas (rankinis pateikimas, vartotojų užsakymų vykdymas ir sekimas)
- nuolaidų katalogas
- atsiskaitymai paypal ir paysera (mokėjimai.lt)

atliekame serverio pradinį paruošimą, aptarnavimą ir monitoringą. konsultuojame serverio įsigijimo klausimais, padedame specifikuoti ir išsirinkti. specializuojamės linux, unix, windows sistemose.

linux redhat/centos/unbreakable/suse
- konfigūravimas
- pradinis diegimas
- soft raid
- monitoringas
- apsauga
- disko kodavimas

elektroninio pašto siuntimo funkcija visiems yra gerai žinoma, daugelis naudojasi interneto tiekėjų paslaugomis. siūlome sprendimą skirtą tiems, kurie nori būti tikri dėl visapusiško savo duomenų privatumo. serveris diegiamas kliento prieigoje arba pasirinktame nuomojamame serveryje. jame talpinamas e-pašto turinys, registras, papildomos apsaugos ar funkcijos:
- antivirusinė apsauga
- brukalo (spam) filtras ir automatizuotas valdymas (naikinti, grąžinti, kaupti vienoje dėžutėje)
- neribotas dėžučių skaičius
- prieinamumas visais žinomais protokolais: pop3, imap, www
- dinaminė ugniasienė
- kiti mechanizmai: postgrey, rbl

Mes kuriame internetines svetaines, elektronines parduotuves, intraneto aplikacijas. Taip pat prižiūrime serverius, juos diegiame. Galime įdiegti papildomus serverio servisus kaip e-pašto funkcija ar statistikos rinkimas.
Internetinės svetainės kuriamos naudojant modulinę turinio valdymo sistemą, Jums sukomplektuojamos reikalingos funkcijos. Svetainė yra automatiškai SEO optimizuota paieškoms ir nereikalauja jokios rankinės priežiūros. Jeigu reikia galima užpildyti ir turinį.
Įmonių aplikacijų pavyzdžiai: CRM, sandėlio valdymas, sąskaitų generavimas, laiko apskaita, intranetas, forumas, registracijos forma, klientų atsiliepimų ar problemų registravimo sistema. Galime suprogramuoti bet kokią jums reikalingą sistemą.