Mailing List Archive

Author: des
Date: 2007-06-29 16:05:49 +0200 (Fri, 29 Jun 2007)
New Revision: 1603

Modified:
trunk/varnish-tools/regress/lib/Varnish/Test/Case/LRU.pm
Log:
Greatly improve this test; see $DESCR + comments for details.


Modified: trunk/varnish-tools/regress/lib/Varnish/Test/Case/LRU.pm
===================================================================
--- trunk/varnish-tools/regress/lib/Varnish/Test/Case/LRU.pm 2007-06-29 14:05:21 UTC (rev 1602)
+++ trunk/varnish-tools/regress/lib/Varnish/Test/Case/LRU.pm 2007-06-29 14:05:49 UTC (rev 1603)
@@ -33,18 +33,24 @@
use strict;
use base 'Varnish::Test::Case';

-use Data::Dumper;
+our $prefix = __PACKAGE__;

# Number of repetitions; total size of data set will be approximately
# (25 * $repeat * $repeat), and needs to be larger than the size of
# the storage file for the test to be meaningful.
our $repeat = 256;

+our $DESCR = "Tests the LRU code by running more data through Varnish" .
+ " than the cache can hold, while simultaneously repeatedly requesting" .
+ " one particular object, which should remain in cache throughout. The" .
+ " total amount of space consumed is approximately $repeat * round(" .
+ ((length(__PACKAGE__) + 5) * $repeat) . ", PAGE_SIZE).";
+
sub _testLRU($$) {
my ($self, $n) = @_;

my $client = $self->new_client();
- my $uri = "/Varnish/Test/Case/LRU/$n";
+ my $uri = __PACKAGE__ . "::$n";
my $request = HTTP::Request->new('GET', $uri);
$request->protocol('HTTP/1.1');
$client->send_request($request, 2);
@@ -65,21 +71,36 @@
sub testLRU($) {
my ($self) = @_;

+ my $response = $self->_testLRU(0);
+ die "Invalid X-Varnish in response"
+ unless $response->header("X-Varnish") =~ m/^(\d+)$/;
+ my $xid0 = $1;
+
# Send $repeat requests in an attempt to eat through the entire
- # storage file.
+ # storage file. Keep one object hot throughout.
#
- # XXX We should check to see if the child dies while we do this.
- # XXX Currently, we will most likely get a client_timeout when
- # XXX testing a pre-LRU version of Varnish.
- for (my $n = 0; $n < $repeat; ++$n) {
+ #XXX We should check to see if the child dies while we do this.
+ #XXX Currently, when testing a pre-LRU version of Varnish, we will
+ #XXX most likely get a client timeout and the test framework will
+ #XXX get stuck.
+ for (my $n = 1; $n < $repeat; ++$n) {
+ # cold object
$self->_testLRU($n);
+
+ # Slow down! If we run through the cache faster than the
+ # hysteresis in the LRU code, the hot object will be evicted.
+ $self->usleep(100000);
+
+ # hot object
+ $response = $self->_testLRU(0);
+ die "Cache miss on hot object"
+ unless $response->header("X-Varnish") =~ m/^(\d+)\s+($xid0)$/o;
}

- # Redo the first request; if we get a cached response (indicated
- # by a second XID in X-Varnish), the test is inconclusive and
- # needs to be re-run with either a smaller storage file or a
- # larger value for $repeat.
- my $response = $self->_testLRU(0);
+ # Re-request an object which should have been evicted. If we get
+ # a cache hit, the test is inconclusive and needs to be re-run
+ # with a smaller storage file or a larger value of $repeat.
+ $response = $self->_testLRU(1);
die "Inconclusive test\n"
unless $response->header("X-Varnish") =~ m/^(\d+)$/;

@@ -92,7 +113,8 @@
my $body = $request->uri() x $repeat;
my $response = HTTP::Response->new(200, undef,
[ 'Content-Type', 'text/plain',
- 'Content-Length', length($body) ],
+ 'Content-Length', length($body),
+ 'Cache-Control', 'max-age=3600', ],
$body);
$response->protocol('HTTP/1.1');
$connection->send_response($response);