Bug 956230: improve instrumentation of bugzilla's internals

8 files changed, 731 insertions, 0 deletions

diff --git a/Bugzilla/Metrics/Collector.pm b/Bugzilla/Metrics/Collector.pm
new file mode 100644
index 000000000..7b2fc3f1b
--- /dev/null
+++ b/Bugzilla/Metrics/Collector.pm
@@ -0,0 +1,160 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Metrics::Collector;
+
+use strict;
+use warnings;
+
+# the reporter needs to be a constant and use'd here to ensure it's loaded at
+# compile time.
+use constant REPORTER => 'Bugzilla::Metrics::Reporter::ElasticSearch';
+use Bugzilla::Metrics::Reporter::ElasticSearch;
+
+# Debugging reporter
+#use constant REPORTER => 'Bugzilla::Metrics::Reporter::STDERR';
+#use Bugzilla::Metrics::Reporter::STDERR;
+
+use File::Basename;
+use Time::HiRes qw(gettimeofday clock_gettime CLOCK_MONOTONIC);
+
+sub new {
+    my ($class, $name) = @_;
+    my $self = {
+        root => undef,
+        head => undef,
+        time => scalar(gettimeofday()),
+    };
+    bless($self, $class);
+    $self->_start_timer({ type => 'main', name => $name });
+    return $self;
+}
+
+sub end {
+    my ($self, $timer) = @_;
+    my $is_head = $timer ? 0 : 1;
+    $timer ||= $self->{head};
+    $timer->{duration} += clock_gettime(CLOCK_MONOTONIC) - $timer->{start_time};
+    $self->{head} = $self->{head}->{parent} if $is_head;
+}
+
+sub DESTROY {
+    my ($self) = @_;
+    $self->finish() if $self->{head};
+}
+
+sub finish {
+    my ($self) = @_;
+    $self->end($self->{root});
+    delete $self->{head};
+
+    my $user = Bugzilla->user;
+    if ($ENV{MOD_PERL}) {
+        require Apache2::RequestUtil;
+        my $request = eval { Apache2::RequestUtil->request };
+        my $headers = $request ? $request->headers_in() : {};
+        $self->{env} = {
+            referer         => $headers->{Referer},
+            request_method  => $request->method,
+            request_uri     => basename($request->unparsed_uri),
+            script_name     => $request->uri,
+            user_agent      => $headers->{'User-Agent'},
+        };
+    }
+    else {
+        $self->{env} = {
+            referer         => $ENV{HTTP_REFERER},
+            request_method  => $ENV{REQUEST_METHOD},
+            request_uri     => $ENV{REQUEST_URI},
+            script_name     => basename($ENV{SCRIPT_NAME}),
+            user_agent      => $ENV{HTTP_USER_AGENT},
+        };
+    }
+    $self->{env}->{name}    = $self->{root}->{name};
+    $self->{env}->{time}    = $self->{time};
+    $self->{env}->{user_id} = $user->id;
+    $self->{env}->{login}   = $user->login if $user->id;
+
+    # remove passwords from request_uri
+    $self->{env}->{request_uri} =~ s/\b((?:bugzilla_)?password=)(?:[^&]+|.+$)/$1x/gi;
+
+    $self->report();
+}
+
+sub name {
+    my ($self, $value) = @_;
+    $self->{root}->{name} = $value if defined $value;
+    return $self->{root}->{name};
+}
+
+sub db_start {
+    my ($self) = @_;
+    my $timer = $self->_start_timer({ type => 'db' });
+
+    my @stack;
+    my $i = 0;
+    while (1) {
+        my @caller = caller($i);
+        last unless @caller;
+        last if substr($caller[1], -5, 5) eq '.tmpl';
+        push @stack, "$caller[1]:$caller[2]"
+            unless substr($caller[1], 0, 16) eq 'Bugzilla/Metrics';
+        $i++;
+    }
+    $timer->{stack} = \@stack;
+
+    return $timer;
+}
+
+sub template_start {
+    my ($self, $file) = @_;
+    $self->_start_timer({ type => 'tmpl', file => $file });
+}
+
+sub memcached_start {
+    my ($self, $key) = @_;
+    $self->_start_timer({ type => 'memcached', key => $key });
+}
+
+sub memcached_end {
+    my ($self, $hit) = @_;
+    $self->{head}->{result} = $hit ? 'hit' : 'miss';
+    $self->end();
+}
+
+sub resume {
+    my ($self, $timer) = @_;
+    $timer->{start_time} = clock_gettime(CLOCK_MONOTONIC);
+    return $timer;
+}
+
+sub _start_timer {
+    my ($self, $timer) = @_;
+    $timer->{start_time} = $timer->{first_time} = clock_gettime(CLOCK_MONOTONIC);
+    $timer->{duration} = 0;
+    $timer->{children}   = [];
+
+    if ($self->{head}) {
+        $timer->{parent} = $self->{head};
+        push @{ $self->{head}->{children} }, $timer;
+    }
+    else {
+        $timer->{parent} = undef;
+        $self->{root} = $timer;
+    }
+    $self->{head} = $timer;
+
+    return $timer;
+}
+
+sub report {
+    my ($self) = @_;
+    my $class = REPORTER;
+    $class->DETACH ? $class->background($self) : $class->foreground($self);
+}
+
+1;
diff --git a/Bugzilla/Metrics/Memcached.pm b/Bugzilla/Metrics/Memcached.pm
new file mode 100644
index 000000000..8dccdb323
--- /dev/null
+++ b/Bugzilla/Metrics/Memcached.pm
@@ -0,0 +1,23 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Metrics::Memcached;
+
+use strict;
+use warnings;
+
+use parent 'Bugzilla::Memcached';
+
+sub _get {
+    my $self = shift;
+    Bugzilla->metrics->memcached_start($_[0]);
+    my $result = $self->SUPER::_get(@_);
+    Bugzilla->metrics->memcached_end($result);
+    return $result;
+}
+
+1;
diff --git a/Bugzilla/Metrics/Mysql.pm b/Bugzilla/Metrics/Mysql.pm
new file mode 100644
index 000000000..7719d1cac
--- /dev/null
+++ b/Bugzilla/Metrics/Mysql.pm
@@ -0,0 +1,148 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Metrics::Mysql;
+
+use 5.10.1;
+use strict;
+use warnings;
+
+use parent 'Bugzilla::DB::Mysql';
+
+sub do {
+    my ($self, @args) = @_;
+    Bugzilla->metrics->db_start($args[0]);
+    my $result = $self->SUPER::do(@args);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+sub selectall_arrayref {
+    my ($self, @args) = @_;
+    Bugzilla->metrics->db_start($args[0]);
+    my $result = $self->SUPER::selectall_arrayref(@args);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+sub selectall_hashref {
+    my ($self, @args) = @_;
+    Bugzilla->metrics->db_start($args[0]);
+    my $result = $self->SUPER::selectall_hashref(@args);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+sub selectcol_arrayref {
+    my ($self, @args) = @_;
+    Bugzilla->metrics->db_start($args[0]);
+    my $result = $self->SUPER::selectcol_arrayref(@args);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+sub selectrow_array {
+    my ($self, @args) = @_;
+    Bugzilla->metrics->db_start($args[0]);
+    my @result = $self->SUPER::selectrow_array(@args);
+    Bugzilla->metrics->end();
+    return wantarray ? @result : $result[0];
+}
+
+sub selectrow_arrayref {
+    my ($self, @args) = @_;
+    Bugzilla->metrics->db_start($args[0]);
+    my $result = $self->SUPER::selectrow_arrayref(@args);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+sub selectrow_hashref {
+    my ($self, @args) = @_;
+    Bugzilla->metrics->db_start($args[0]);
+    my $result = $self->SUPER::selectrow_hashref(@args);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+sub commit {
+    my ($self, @args) = @_;
+    Bugzilla->metrics->db_start('COMMIT');
+    my $result = $self->SUPER::commit(@args);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+sub prepare {
+    my ($self, @args) = @_;
+    my $sth = $self->SUPER::prepare(@args);
+    bless($sth, 'Bugzilla::Metrics::st');
+    return $sth;
+}
+
+package Bugzilla::Metrics::st;
+
+use 5.10.1;
+use strict;
+use warnings;
+
+use base 'DBI::st';
+
+sub execute {
+    my ($self, @args) = @_;
+    $self->{private_timer} = Bugzilla->metrics->db_start();
+    my $result = $self->SUPER::execute(@args);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+sub fetchrow_array {
+    my ($self, @args) = @_;
+    my $timer = $self->{private_timer};
+    Bugzilla->metrics->resume($timer);
+    my @result = $self->SUPER::fetchrow_array(@args);
+    Bugzilla->metrics->end($timer);
+    return wantarray ? @result : $result[0];
+}
+
+sub fetchrow_arrayref {
+    my ($self, @args) = @_;
+    my $timer = $self->{private_timer};
+    Bugzilla->metrics->resume($timer);
+    my $result = $self->SUPER::fetchrow_arrayref(@args);
+    Bugzilla->metrics->end($timer);
+    return $result;
+}
+
+sub fetchrow_hashref {
+    my ($self, @args) = @_;
+    my $timer = $self->{private_timer};
+    Bugzilla->metrics->resume($timer);
+    my $result = $self->SUPER::fetchrow_hashref(@args);
+    Bugzilla->metrics->end($timer);
+    return $result;
+}
+
+sub fetchall_arrayref {
+    my ($self, @args) = @_;
+    my $timer = $self->{private_timer};
+    Bugzilla->metrics->resume($timer);
+    my $result = $self->SUPER::fetchall_arrayref(@args);
+    Bugzilla->metrics->end($timer);
+    return $result;
+}
+
+sub fetchall_hashref {
+    my ($self, @args) = @_;
+    my $timer = $self->{private_timer};
+    Bugzilla->metrics->resume($timer);
+    my $result = $self->SUPER::fetchall_hashref(@args);
+    Bugzilla->metrics->end($timer);
+    return $result;
+}
+
+1;
diff --git a/Bugzilla/Metrics/Reporter.pm b/Bugzilla/Metrics/Reporter.pm
new file mode 100644
index 000000000..42d2c3abc
--- /dev/null
+++ b/Bugzilla/Metrics/Reporter.pm
@@ -0,0 +1,101 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Metrics::Reporter;
+
+use strict;
+use warnings;
+
+use Bugzilla::Constants;
+use File::Slurp;
+use File::Temp;
+use JSON;
+
+# most reporters should detach from the httpd process.
+# reporters which do not detach will block completion of the http response.
+use constant DETACH => 1;
+
+# class method to start the delivery script in the background
+sub background {
+    my ($class, $collector) = @_;
+
+    # we need to remove parent links to avoid looped structures, which
+    # encode_json chokes on
+    _walk_timers($collector->{root}, sub { delete $_[0]->{parent} });
+
+    # serialisation
+    my $json = encode_json({ env => $collector->{env}, times => $collector->{root} });
+
+    # write to temp filename
+    my $fh = File::Temp->new( UNLINK => 0 );
+    if (!$fh) {
+        warn "Failed to create temp file: $!\n";
+        return;
+    }
+    binmode($fh, ':utf8');
+    print $fh $json;
+    close($fh) or die "$fh : $!";
+    my $filename = $fh->filename;
+
+    # spawn delivery worker
+    my $command = bz_locations()->{'cgi_path'} . "/metrics.pl '$class' '$filename' &";
+    system($command);
+}
+
+# run the reporter immediately
+sub foreground {
+    my ($class, $collector) = @_;
+    my $reporter = $class->new({ hashref => { env => $collector->{env}, times => $collector->{root} } });
+    $reporter->report();
+}
+
+sub new {
+    my ($invocant, $args) = @_;
+    my $class = ref($invocant) || $invocant;
+
+    # load from either a json_filename or hashref
+    my $self;
+    if ($args->{json_filename}) {
+        $self = decode_json(read_file($args->{json_filename}, binmode => ':utf8'));
+        unlink($args->{json_filename});
+    }
+    else {
+        $self = $args->{hashref};
+    }
+    bless($self, $class);
+
+    # remove redundant data
+    $self->walk_timers(sub {
+        my ($timer) = @_;
+        $timer->{start_time} = delete $timer->{first_time};
+        delete $timer->{children}
+            if exists $timer->{children} && !scalar(@{ $timer->{children} });
+    });
+
+    return $self;
+}
+
+sub walk_timers {
+    my ($self, $callback) = @_;
+    _walk_timers($self->{times}, $callback, undef);
+}
+
+sub _walk_timers {
+    my ($timer, $callback, $parent) = @_;
+    $callback->($timer, $parent);
+    if (exists $timer->{children}) {
+        foreach my $child (@{ $timer->{children} }) {
+            _walk_timers($child, $callback, $timer);
+        }
+    }
+}
+
+sub report {
+    die "abstract method call";
+}
+
+1;
diff --git a/Bugzilla/Metrics/Reporter/ElasticSearch.pm b/Bugzilla/Metrics/Reporter/ElasticSearch.pm
new file mode 100644
index 000000000..4b424b5da
--- /dev/null
+++ b/Bugzilla/Metrics/Reporter/ElasticSearch.pm
@@ -0,0 +1,96 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Metrics::Reporter::ElasticSearch;
+
+use strict;
+use warnings;
+
+use parent 'Bugzilla::Metrics::Reporter';
+
+use constant DETACH => 1;
+
+sub report {
+    my ($self) = @_;
+
+    # build path array and flatten
+    my @timers;
+    $self->walk_timers(sub {
+        my ($timer, $parent) = @_;
+        $timer->{id} = scalar(@timers);
+        if ($parent) {
+            if (exists $timer->{children}) {
+                if ($timer->{type} eq 'tmpl') {
+                    $timer->{node} = 'tmpl: ' . $timer->{file};
+                }
+                elsif ($timer->{type} eq 'db') {
+                    $timer->{node} = 'db';
+                }
+                else {
+                    $timer->{node} = '?';
+                }
+            }
+            $timer->{path} = [ @{ $parent->{path} }, $parent->{node} ];
+            $timer->{parent} = $parent->{id};
+        }
+        else {
+            $timer->{path} = [ ];
+            $timer->{node} = $timer->{name};
+        }
+        push @timers, $timer;
+    });
+
+    # calculate timer-only durations
+    $self->walk_timers(sub {
+        my ($timer) = @_;
+        my $child_duration = 0;
+        if (exists $timer->{children}) {
+            foreach my $child (@{ $timer->{children} }) {
+                $child_duration += $child->{duration};
+            }
+        }
+        $timer->{this_duration} = $timer->{duration} - $child_duration;
+    });
+
+    # massage each timer
+    my $start_time = $self->{times}->{start_time};
+    foreach my $timer (@timers) {
+        # remove node name and children
+        delete $timer->{node};
+        delete $timer->{children};
+
+        # show relative times
+        $timer->{start_time} = $timer->{start_time} - $start_time;
+        delete $timer->{end_time};
+
+        # show times in ms instead of fractional seconds
+        foreach my $field (qw( start_time duration this_duration )) {
+            $timer->{$field} = sprintf('%.4f', $timer->{$field} * 1000) * 1;
+        }
+    }
+
+    # remove private data from env
+    delete $self->{env}->{user_agent};
+    delete $self->{env}->{referer};
+
+    # throw at ES
+    require ElasticSearch;
+    ElasticSearch->new(
+        servers     => Bugzilla->params->{metrics_elasticsearch_server},
+        transport   => 'http',
+    )->index(
+        index   => Bugzilla->params->{metrics_elasticsearch_index},
+        type    => Bugzilla->params->{metrics_elasticsearch_type},
+        ttl     => Bugzilla->params->{metrics_elasticsearch_ttl},
+        data    => {
+            env     => $self->{env},
+            times   => \@timers,
+        },
+    );
+}
+
+1;
diff --git a/Bugzilla/Metrics/Reporter/STDERR.pm b/Bugzilla/Metrics/Reporter/STDERR.pm
new file mode 100644
index 000000000..f5bd38acb
--- /dev/null
+++ b/Bugzilla/Metrics/Reporter/STDERR.pm
@@ -0,0 +1,151 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Metrics::Reporter::STDERR;
+
+use strict;
+use warnings;
+
+use parent 'Bugzilla::Metrics::Reporter';
+
+use Data::Dumper;
+
+use constant DETACH => 0;
+
+sub report {
+    my ($self) = @_;
+
+    # count totals
+    $self->{total} = $self->{times}->{duration};
+    $self->{tmpl_count} = $self->{db_count} = $self->{mem_count} = 0;
+    $self->{total_tmpl} = $self->{total_db} = $self->{mem_hits}  = 0;
+    $self->{mem_keys} = {};
+    $self->_tally($self->{times});
+
+    # calculate percentages
+    $self->{other} = $self->{total} - $self->{total_tmpl} - $self->{total_db};
+    if ($self->{total} * 1) {
+        $self->{perc_tmpl}  = $self->{total_tmpl} / $self->{total} * 100;
+        $self->{perc_db}    = $self->{total_db} / $self->{total} * 100;
+        $self->{perc_other} = $self->{other} / $self->{total} * 100;
+    } else {
+        $self->{perc_tmpl} = 0;
+        $self->{perc_db} = 0;
+        $self->{perc_other} = 0;
+    }
+    if ($self->{mem_count}) {
+        $self->{perc_mem} = $self->{mem_hits} / $self->{mem_count} * 100;
+    } else {
+        $self->{perm_mem} = 0;
+    }
+
+    # convert to ms and format
+    foreach my $key (qw( total total_tmpl total_db other )) {
+        $self->{$key} = sprintf("%.4f", $self->{$key} * 1000);
+    }
+    foreach my $key (qw( perc_tmpl perc_db perc_other perc_mem )) {
+        $self->{$key} = sprintf("%.1f", $self->{$key});
+    }
+
+    # massage each timer
+    my $start_time = $self->{times}->{start_time};
+    $self->walk_timers(sub {
+        my ($timer) = @_;
+        delete $timer->{parent};
+
+        # show relative times
+        $timer->{start_time} = $timer->{start_time} - $start_time;
+        delete $timer->{end_time};
+
+        # show times in ms instead of fractional seconds
+        foreach my $field (qw( start_time duration duration_this )) {
+            $timer->{$field} = sprintf('%.4f', $timer->{$field} * 1000) * 1
+                if exists $timer->{$field};
+        }
+    });
+
+    if (0) {
+        # dump timers to stderr
+        local $Data::Dumper::Indent = 1;
+        local $Data::Dumper::Terse = 1;
+        local $Data::Dumper::Sortkeys = sub {
+            my ($rh) = @_;
+            return [ sort { $b cmp $a } keys %$rh ];
+        };
+        print STDERR Dumper($self->{env});
+        print STDERR Dumper($self->{times});
+    }
+
+    # summary summary table too
+    print STDERR <<EOF;
+total time: $self->{total}
+ tmpl time: $self->{total_tmpl} ($self->{perc_tmpl}%) $self->{tmpl_count} hits
+   db time: $self->{total_db} ($self->{perc_db}%) $self->{db_count} hits
+other time: $self->{other} ($self->{perc_other}%)
+ memcached: $self->{perc_mem}% ($self->{mem_count} requests)
+EOF
+    my $tmpls = $self->{tmpl};
+    my $len = 0;
+    foreach my $file (keys %$tmpls) {
+        $len = length($file) if length($file) > $len;
+    }
+    foreach my $file (sort { $tmpls->{$b}->{count} <=> $tmpls->{$a}->{count} } keys %$tmpls) {
+        my $tmpl = $tmpls->{$file};
+        printf STDERR
+            "%${len}s: %2s hits %8.4f total %8.4f avg\n",
+            $file,
+            $tmpl->{count},
+            $tmpl->{duration} * 1000,
+            $tmpl->{duration} * 1000 / $tmpl->{count}
+        ;
+    }
+    my $keys = $self->{mem_keys};
+    $len = 0;
+    foreach my $key (keys %$keys) {
+        $len = length($key) if length($key) > $len;
+    }
+    foreach my $key (sort { $keys->{$a} <=> $keys->{$b} or $a cmp $b } keys %$keys) {
+        printf STDERR "%${len}s: %s\n", $key, $keys->{$key};
+    }
+}
+
+sub _tally {
+    my ($self, $timer) = @_;
+    if (exists $timer->{children}) {
+        foreach my $child (@{ $timer->{children} }) {
+            $self->_tally($child);
+        }
+    }
+
+    if ($timer->{type} eq 'db') {
+        $timer->{duration_this} = $timer->{duration};
+        $self->{total_db} += $timer->{duration};
+        $self->{db_count}++;
+
+    } elsif ($timer->{type} eq 'tmpl') {
+        my $child_duration = 0;
+        if (exists $timer->{children}) {
+            foreach my $child (@{ $timer->{children} }) {
+                $child_duration += $child->{duration};
+            }
+        }
+        $timer->{duration_this} = $timer->{duration} - $child_duration;
+
+        $self->{total_tmpl} += $timer->{duration} - $child_duration;
+        $self->{tmpl_count}++;
+        $self->{tmpl}->{$timer->{file}}->{count}++;
+        $self->{tmpl}->{$timer->{file}}->{duration} += $timer->{duration};
+
+    } elsif ($timer->{type} eq 'memcached') {
+        $timer->{duration_this} = $timer->{duration};
+        $self->{mem_count}++;
+        $self->{mem_keys}->{$timer->{key}}++;
+        $self->{mem_hits}++ if $timer->{result} eq 'hit';
+    }
+}
+
+1;
diff --git a/Bugzilla/Metrics/Template.pm b/Bugzilla/Metrics/Template.pm
new file mode 100644
index 000000000..a3b13f85d
--- /dev/null
+++ b/Bugzilla/Metrics/Template.pm
@@ -0,0 +1,23 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Metrics::Template;
+
+use strict;
+use warnings;
+
+use parent 'Bugzilla::Template';
+
+sub process {
+    my $self = shift;
+    Bugzilla->metrics->template_start($_[0]);
+    my $result = $self->SUPER::process(@_);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+1;
diff --git a/Bugzilla/Metrics/Template/Context.pm b/Bugzilla/Metrics/Template/Context.pm
new file mode 100644
index 000000000..ae8470b3f
--- /dev/null
+++ b/Bugzilla/Metrics/Template/Context.pm
@@ -0,0 +1,29 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::Metrics::Template::Context;
+
+use strict;
+use warnings;
+
+use parent 'Bugzilla::Template::Context';
+
+sub process {
+    my $self = shift;
+
+    # we only want to measure files not template blocks
+    if (ref($_[0]) || substr($_[0], -5) ne '.tmpl') {
+        return $self->SUPER::process(@_);
+    }
+
+    Bugzilla->metrics->template_start($_[0]);
+    my $result = $self->SUPER::process(@_);
+    Bugzilla->metrics->end();
+    return $result;
+}
+
+1;