Zeus KnowledgeHub - Last comments

In response to: Ruby and SOAP Revisited

Jonathan Lambert — Thu, 04 Mar 2010 07:03:58 +0000

Um, thanks. You couldn't have been more helpful.

In response to: Reading data from external files and tables

Patrick Mooney — Fri, 26 Feb 2010 10:10:05 +0000

Is there best practice to the number of items we should (max) place in an external file for performance?

In response to: Multi-hosted IP Addresses with Zeus Software

mrz — Sun, 21 Feb 2010 06:16:10 +0000

If you have more than one cluster, take care to manually adjust the multicast IP address, which in turn generates the multicast MAC address.

If you skip that you'll have address collision which is network wide, not just limited to a subnet (mostly because of the issues under the FAQ under "Switch Compatibility Issues").

In response to: Why can't users connect to my multi-hosted IPs?

mrz — Sun, 21 Feb 2010 06:07:35 +0000

These instructions are missing some details.

1. Any attached Layer 3 device will need to have a static arp entry. This will most commonly be the router or default gateway but will include any other hosts on the same subnet.

2. Any Layer 2 device will need to have a static MAC entry. It may not be enough to add static MAC entries to just the connected switch, however. You may need to make sure that all switches can properly flood to all switches.

A couple other notes:

1. On Cisco switches you'll need to disable igmp snooping. In IOS,



no  ip igmp snooping

2. On Juniper switches, you'll need:



 delete protocols igmp-snooping

In response to: TCP Checksum errors

Raghu Gandham — Thu, 18 Feb 2010 04:30:52 +0000

Ok.. I missed the point that the error message was Operation not supported. This happens if the ethernet driver does not support setting of rx csum value.

In response to: TCP Checksum errors

Raghu Gandham — Thu, 18 Feb 2010 04:28:13 +0000

Are you sure you are doing this as root ?

In response to: Zeus Traffic Manager 6.0r3 released; other supported versions updated

Owen Garrett [Zeus Dev Team] — Thu, 21 Jan 2010 17:21:17 +0000

These are updated now - apologies.

In response to: Zeus Traffic Manager 6.0r3 released; other supported versions updated

Subramanyam Chitti — Thu, 21 Jan 2010 15:03:33 +0000

From Development License downloads page is still 6.0r2?

In response to: Receiving SMS Alerts from ZXTM

andy knox [Zeus Dev Team] — Fri, 15 Jan 2010 16:32:12 +0000

The token IP idea should work as long as every machine in your traffic manager cluster can raise that IP. It doesn't matter if that IP can actually be contacted or not. You can happily use a 192.168. or 10. IP if there is an interface on each machine that already has an IP on that subnet.

If the machine that has the token IP raised fails, another machine will detect its failure and raise the IP itself. There will therefore always be one and only one machine in the cluster at any time that has the IP and that will send you messages.

Hope that answers your question!

In response to: Receiving SMS Alerts from ZXTM

kpfoote — Fri, 15 Jan 2010 16:16:44 +0000

Thanks Andy this is just what I needed..

I'm using a variation of this to send a much more meaningful sms to myself.
Nice!

One question on the example of the token ip.. Does this need to be a routeable
IP? I can't see having something take up an ip just for the heck of it.. Is a 192.168 or 10. acceptable for this even if the rest of my zxtm config lives in our routeable space.

In response to: Using Events to Debug Problems

andy knox [Zeus Dev Team] — Tue, 12 Jan 2010 17:15:56 +0000

The best way to achieve this is probably to use a Perl SMTP library, such as Net::SMTP, and add some extra logic to the end of the script to e-mail you the debug data. The Net::SNMP library is usually included with a standard perl installation and is also available on our appliances.

You can find documentation for it here:
http://perldoc.perl.org/Net/SMTP.html

It's very simple to use and will hopefully solve your problem!

If you really want to use the E-Mail Action inside the traffic manager though, you could create a new HTTP Virtual Server that listens on a local IP. If you add a rule to the Virtual Server with the line:

event.emit( "debug-data", http.getBody() );

then any body data contained in a HTTP request to that Virtual Server will be raised in the debug-data event. If you map this event to the E-Mail Action then you will be e-mailed the data.

You can then add some extra logic to the Perl script to use the http client provided with the traffic manager (found in $ZEUSHOME/admin/bin/httpclient) to send the debug output to the new Virtual Server and it will then be e-mailed to you!

Hope this helps!

In response to: Using Events to Debug Problems

kpfoote — Tue, 12 Jan 2010 16:16:58 +0000

This is great. Any chance you can use the zxtm's ability to send email to send the debug report to someone or some group? This would be instead of the scp.

In response to: Sending custom error pages

Owen Garrett [Zeus Dev Team] — Mon, 04 Jan 2010 10:39:20 +0000

From Twitter:

kevinfoote: ok. got my poor man's maintenance page setup done. using RuleBuilder and a maintenance pool http://www.tinyurl.com/ydkj7nn maybe some interest..

Thanks Kevin!

In response to: IP Transparency with the ZXTM software

Harry — Sun, 03 Jan 2010 09:17:20 +0000

Made some source fixups for 2.6.31.9, seems to work fine.

See: http://paste2.org/p/591581 for the diff

In response to: List running Virtual Servers using Ruby and SOAP

Dan Sketcher — Wed, 16 Dec 2009 00:51:08 +0000

I've integrated this into a class for easy use:

http://github.com/touchlocal/ruby_zxtm_manager

In response to: Building a MySQL load-balancing proxy with TrafficScript

Jim Grill — Sat, 28 Nov 2009 22:50:47 +0000

if you want to add a nice error message anywhere inside a traffic script, here is an example auth error packet (slightly out of context for demonstration purposes):

[code]
# simulated auth error packet
$authError = "\0\0\0\2" . # length + packet no (correct length later)
"\377" . # field_count, always = 0xff (255 decimal)
"\25\04" . # errno 1045 (little endian)
"\043" . # (sqlstate marker), always '#'
"\062\070\60\60\60"; # sqlstate (5 characters)
# error message # append errmsg later

$remoteIP = request.getremoteip();
$usingPw = "YES";
if ($encpasswd == "" ) $usingPw = "NO";

$msg = "Access denied to ZXTM server for user '" .
$user . "'@'" . $remoteIP ."' (using password: " . $usingPw . ")";

# append msg to authError packet and terminate packet
$authError .= $msg . "\0";
# rewrite first byte to size of packet (less header)
$len = string.length( $authError )-4;
$authError = string.replaceBytes( $authError, string.intToBytes( $len, 1 ), 0 );

# send auth err packet to client and close connection
connection.close( $authError);
[/code]

While the above is formatted as an auth error packet, there is no structural difference between this and any type of erorr packet. This could easily be modified to be any type of error message you'd like to send the mysql client.

You can change the error code, sql state and error message to suite your needs. Just remember that the error number is a two byte little endian while the sql state is ascii characters in octal. Tweeking the packet number might also be necessary, depending on what has been sent to the client already.

If you want to have some fun with your users, try out some "custom" error messages like "do you know what you're doing?" or "please deposit 25 cents to continue" :)

In response to: Building a MySQL load-balancing proxy with TrafficScript

Owen Garrett [Zeus Dev Team] — Fri, 20 Nov 2009 00:12:54 +0000

Jim's got it working now... well done!

The other 'gotcha' he found was that in the mysql user table, the long passwords start with a '*'. This is not part of the encoded password, so don't copy it into the TrafficScript rule!

I've added a comment to the rule to help avoid this in future.

In response to: Building a MySQL load-balancing proxy with TrafficScript

Owen Garrett [Zeus Dev Team] — Thu, 19 Nov 2009 15:54:18 +0000

Hi Jim,

Problem 1 - in version 5.1 (December 2008), we added a function called 'randomBytes' to the TrafficScript language, so that should explain the problem you saw. I've updated the example above (just removed the subroutine 'randomBytes') and explained that you need to use version 5.1 or later.

Problem 2 - when you configure the rules, you must remember to set them to run Every time. By default, when you add a rule to a virtual server, it only runs once (when it recieves the first data). There's a toggle button in the Virtual Server's Rules page that must be set to 'Every', not 'Once' for both rules.

One other gotcha - make sure that the user you connect with has the appropriate privileges; I've found it necessary to GRANT... TO 'user'@'%' in some cases.

In response to: Building a MySQL load-balancing proxy with TrafficScript

Jim — Wed, 18 Nov 2009 19:45:16 +0000

This is very cool. I saw the webex today with MySQL and Joyent. Very informative.

I'm having two problems trying to set this up:

1) Error when adding response script to TrafficScript editor "Function 'randombytes' already exists"

2) no matter what I try: ERROR 2013 (HY000): Lost connection to MySQL server at 'reading authorization packet', system error: 0

I changed the name of the function for item 1. I'm still stumped on item 2. Is there a way to get debugging info from a log or something?

In response to: Network Side Scripting - Modifying HTTP requests with Netscaler VPX, F5 BigIP and Zeus Traffic Manager

ctripod [Member] — Thu, 12 Nov 2009 18:17:58 +0000

I created the rewrite action/policy in the GUI. Use REPLACE as your action and then use the Expression to locate the data you would like to manipulate. in this case HTTP.REQ.HOSTNAME which will operate on the Host header value. Matter of fact, AppExpert has an Evaluation interface to ensure the proper result prior to applying these policies to live traffic. If you click the "Evaluate" button below the Expression Field you'll open this interface. You can then input your own HTTP headers or use the "Samples" to input a GET or POST request. Then click "Evaluate" button to apply your expression to the request.

Simplifying difficult Layer 7 tasks to a intuitive structure is a huge advantage and there is no way to hang a box because of bad or novice programmers (as I've seen with others).

As a reference you can copy and paste my configuration lines above into the CLI then login to the GUI and update your screen shots with the appropriate ones. :-)