In this article Barry Mavin explains step by step how to setup a Linux HA (High Availability) cluster for the running of Recital applications on Redhat/Centos 5.3 although the general configuration should work for other linux versions with a few minor changes.
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There is a good article here this describes agile software development techniques. This is what we have always been doing but it's nice to see it defined formally.
We use this technique ourselves on our development portal.
The Komodo Editor is a free project based editor that runs on the mac, linux and windows. It color codes and handles auto completion for lots of languages (including Recital/PHP/Perl/C etc). You can download it free from here.
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If you are running your Redhat/Centos or Fedora machine in an enterprise environment you may be sitting behind a network proxy server like squid.
If you try and update or install software it will fail with timeouts or errors contacting the repository mirrors.
To configure YUM to work with your proxy server you need to add the following line to your /etc/yum.conf file.
Anonymous proxy configuration:
proxy=http://yourproxyip:port/
If your proxy server requires authentication add the following lines to your /etc/yum.conf file instead.
proxy=http://yourproxyip:port/ proxy_username=youruser proxy_password=yourpassword
You will be able to update and install software now, give it a go!
TIP
To access the menu bar in Recital, press the / key.
To access the menu bar in Recital, press the / key.
Full details on Recital Function Keys can be found in the Key Assist section of the Help menu, or in our documentation wiki here.
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lslk lists information about locks held on files with local inodes on systems running linux.
Install it with:
yum install lslk
Opening SSH to the outside world is a security risk. Here is how to restrict SSH access to certain IP addresses on a machine.
- Edit the /etc/hosts.allow file to include these lines, assuming your machine is on the 192.168.2.x nonrouting IP block, and you want to enable an external address of 217.40.111.121 IP block: Remember to add the period on the end of each incomplete IP number. If you have another complete IP address or range, add a space and that range on the end.
sshd,sshdfwd-X11: 192.168.2. 217.40.111.121
- Edit your /etc/hosts.deny file to include this line:
sshd,sshdfwd-X11:ALL
- These lines refuse SSH connections from anyone not in the IP address blocks listed.
Additionally you can restrict SSH access by username.
- Edit the /etc/ssh/sshd_config file and add the following lines
PermitRootLogin no
AllowUsers user1 user2 user3 etc
PasswordAuthentication yes
Now restart the ssh daemon for these changes to take effect
service sshd restart
Recital 10.0 introduced the COPY DATABASE <name> TO <name> command.. The full syntax is;
COPY DATABASE <name> TO <name> [ IF [ NOT ] EXISTS ]This command is used to copy an existing database to a new database. By default an error will be returned if the target database already exists. Specifying the optional IF NOT EXISTS keywords no error will be returned if the target database already exists. If the optional IF EXISTS keywords are specified and the target database already exists, then it will be removed before the copy. Both the databases must be closed before they can be copied.
Each Recital table can have one or more data dictionaries to provide a central repository for constraints and other metadata.
Here's how to set up field validation based on dynamic values from another table.
Using the products.dbf table from the southwind sample database, validation can be added to the categoryid field to ensure it matches an existing categoryid from the categories.dbf table.
If you have access to the Recital Workbench, you can use the modify structure worksurface to add and alter your dictionary entries, including a customized error message if required.
Here's how to set up field validation based on dynamic values from another table.
Using the products.dbf table from the southwind sample database, validation can be added to the categoryid field to ensure it matches an existing categoryid from the categories.dbf table.
open database southwindThe rlookup() function checks whether an expression exists in the index (master or specified) of the specified table . An attempt to update categoryid with a value not in the list will give an error: Validation on field 'CATEGORYID' failed.
alter table products add constraint;
(categoryid set check rlookup(products.categoryid,categories))
If you have access to the Recital Workbench, you can use the modify structure worksurface to add and alter your dictionary entries, including a customized error message if required.