Bouncy castle, in turn requires a highly randomized source from the OS. But Amazon EC2 are virtual environment and thus have very little randomness
As a result, these libraries will hang for a long time, and may never complete
Solution: simply call the os’ natively installed ssh executable. It seems this has been modified to accomodate the environment and work much faster. This also reduced dependency on external libraries (don’t have to download jsch or sshj from maven)
Downside: while Jetmeter is written in java, dependency on ssh and scp means it can only run on MacOS or Linux
If you use JMeter plugins, you need to include those plugins as libraries, increasing the size of the build a lot
You’ll still need to include the JMeter binary and extension directory (yes, you need both build time and run time access)
This is due to historical reasons. JMeter has been developed a long time ago and they couldn’t break old conventions.
Including JMeter in our application will affect
Security. Any JMeter vulnerability will affect our application too
JMeter has a tendency to hang. Once we hand over control to the JMeter library it’s hard to take back, the only way is to fork a new process.
When we go with process forking, it’s hard to monitor the progress of JMeter (you need to constantly check for result files as JMeter provide no internal method for this)
JMeter was built to be mainly run from the command line. To do even basic operation like launching remote controller would require convoluted object instantiation and reflection to access JMeter’s internal types
Solution: Since we need to include JMeter library anyway, just call it as an external application and wait for it to finish
Caliper
When running Caliper via a remote session, caliper sometimes end the session during test (after around 5 seconds), but still running on the remote host
Can’t depend on caliper output
Can’t depend on the time caliper exit thread for control flow
Need to periodically pool caliper report file on remote host
Better reliability: it automatically reconnects when there’s a problem
How? Simple, instead of creating a connection, just create a pool. It’s designed as a drop in replacement for client.query()
var mysql = require('mysql');
var pool = mysql.createPool({
connectionLimit : 10,
host : 'example.org',
user : 'bob',
password : 'secret',
database : 'my_db'
});
pool.query('SELECT 1 + 1 AS solution', function (error, results, fields) {
if (error) throw error;
console.log('The solution is: ', results[0].solution);
});
is a shorthand for
var mysql = require('mysql');
var pool = mysql.createPool(...);
pool.getConnection(function(err, connection) {
if (err) throw err; // not connected!
// Use the connection
connection.query('SELECT something FROM sometable', function (error, results, fields) {
// When done with the connection, release it.
connection.release();
// Handle error after the release.
if (error) throw error;
// Don't use the connection here, it has been returned to the pool.
});
});
As any seasoned webmaster may have known, Cloudflare’s free SSL certificate while convenient for most use cases, are very restrictive in edge cases. For example when you want to have.a.vanity.url.com for your website, Cloudflare won’t work (only vanity.url.com part is permitted).
What can you do? Other than paying cloudflare $10 / month and get a custom-made edge certificate?
http://www.example.com/blog/+ [extra directory before the +] http://www.example.com+ [no trailing slash]
Once you have created the pattern that matches what you want, click the Forwarding toggle. That exposes a field where you can enter the address I want requests forwarded to.
https://plus.google.com/yourid
If I enter that in the forwarding box and click the Add Rule button within a few seconds any requests that match the pattern I entered will automatically be forwarded with a 302 Redirect to the new URL.
Advanced forwarding options:
If you use a basic redirect, such as forwarding the root domain to www.yourdomain.com, then you lose anything else in the URL. For example, you could setup the pattern:
example.com
And have it forward to:
http://www.example.com
But then if someone entered:
example.com/some-particular-page.html
Then they’d be redirected to:
www.example.com
Not where you’d want them to go:
www.example.com/some-particular-page.html
The solution is to use variables. Each wildcard corresponds to a variable when can be referenced in the forwarding address. The variables are represented by a $ followed by a number. To refer to the first wildcard you’d use $1, to refer to the second wildcard you’d use $2, and so on. To fix the forwarding from the root to www in the above example, you could use the same pattern:
example.com/*
You’d then setup the following URL for traffic to forward to:
http://www.example.com/$1
In this case, if someone went to:
example.com/some-particular-page.html
They’d be redirected to:
http://www.example.com/some-particular-page.html
Using this and set up a rule like
$1.$2.yourdomain/$3
and forward it to
yourdomain/$1.$2/$3
You can redirect it somewhere else or create a website for it
