Perlbal::Manual::DebugUser(Contributed Perl DocumPerlbal::Manual::Debugging(3)NAMEPerlbal::Manual::Debugging - Debugging Perlbal
VERSION
Perlbal 1.78.
DESCRIPTION
Perlbal has two ways of debugging.
One of them is through a management console; the other is through
debugging messages.
Debugging in a console
You'll need to set up a management service and use it to dump all the
information you require.
The comprehensive documentation on this process can be found at
Perlbal::Manual::Management.
Debugging messages
You can control the ammount of debugging messages Perlbal dumps by
setting the environment variable "PERLBAL_DEBUG" to a value between 0
and 4:
PERLBAL_DEBUG = 0 # no debug
PERLBAL_DEBUG = 4 # debug everything
Debug level 1
You can activate basic debug by setting "PERLBAL_DEBUG" to 1:
PERLBAL_DEBUG = 1
The following debugging messages are turned on:
· When a connection to a backend is closed, Perlbal::BackendHTTP
prints "Backend $self is done; closing..."
· When a connection to a backend is killed, Perlbal::ClientProxy
prints "Client ($self) closing backend ($backend)"
· When an HTTP request fails to be parsed, Perlbal::HTTPHeaders
prints "HTTP parse failure: $reason"
· When the connection is promoted to SSL, Perlbal::TCPListener prints
" .. socket upgraded to SSL!"
Debug level 2
By setting the debug level to 2 you'll get all the messages from level
1.
PERLBAL_DEBUG = 2
You will also get a few others:
· When a connection to a backend is opened and ready to be written
to, Perlbal::BackendHTTP prints "Backend $self is writeable!"
· When a response is about to be handled, Perlbal::BackendHTTP prints
"BackendHTTP: handle_response"
· When a backend is ready to be read from, Perlbal::BackendHTTP
prints "Backend $self is readable!"
· When there's an error with the connection to the backend,
Perlbal::BackendHTTP prints "BACKEND event_err"
· Whenever we're determining if we should be sending keep-alive
header information back to the client, Perlbal::ClientHTTPBase
prints "ClientHTTPBase::setup_keepalive($self)"
· Whenever the client is ready for more of its file,
Perlbal::ClientHTTPBase prints "REPROXY SSL done"
· Right after we've read a chunk of a file and when a reproxy request
is about to be sent, Perlbal::ClientHTTPBase prints "REPROXY Sent:
$sent"
· When we've written all data in the queue (and are about to stop
waiting for write notifications), Perlbal::ClientHTTPBase prints
"All writing done to $self"
· Whenever a client proxy is about to be closed, Perlbal::ClientProxy
prints "Perlbal::ClientProxy closed", followed by a possible
"again" and a possible "saying $reason"
· When a client has disconnected, Perlbal::ClientProxy prints
"ClientProxy::client_disconnected"
· When a backend requests a client of a high priority request and the
client is available, "Service" in Perlbal prints "Got from fast
queue, in front of $backlog others"
· When a backend requests a client of a normal priority request and
the client is available, "Service" in Perlbal prints "Backend
requesting client, got PRIORITY = $cp-"{fd}.>
· When a backend requests a client of a low priority request and the
client is available, "Service" in Perlbal prints "Backend
requesting client, got low priority = $cp-"{fd}.>
· When header are being read, Perlbal::Socket prints
"Perlbal::Socket::read_headers($self) is_res=$is_res"
Debug level 3
PERLBAL_DEBUG = 3
By setting the debug level to 3 you'll get all the messages from level
1 and 2 plus the following:
· Right before response headers are written to the client,
Perlbal::BackendHTTP prints " writing response headers to client"
· As we're writing to the client, Perlbal::BackendHTTP prints "
content_length=VALUE" and " remain=VALUE", where the values are
"undef" if they are not defined
· If we're done writing to the client, Perlbal::BackendHTTP prints "
done. detaching."
· Whenever we're determining if we should be sending keep-alive
header information back to the client, Perlbal::ClientHTTPBase
prints " service's persist_client = $persist_client"
· While determining if we should be sending keep-alive header
information back to the client, if we were sent "content-length" or
it's a head request, as we're doing a keep alive
Perlbal::ClientHTTPBase prints " doing keep-alive to client"
· If we're not sending keep-alive header information back ot the
client, Perlbal::ClientHTTPBase prints " doing connection: close"
· Right after we've finished sending all of the results to the user,
Perlbal::ClientProxy prints "ClientProxy::backend_finished"
· When we've sent a response to a user fully and we need to reset
state, Perlbal::ClientProxy prints "ClientProxy::http_response_sent
-- resetting state"
· When we're writing a response to a client, Perlbal::ClientProxy
prints "ClientProxy::event_write"
· After writing a response to a client, if it is still connected and
we're triggering trigger our backend to keep reading,
Perlbal::ClientProxy prints " unstalling backend"
· When reading a request, Perlbal::ClientProxy prints
"ClientProxy::event_read"
· When reading a request and just before we read the headers,
Perlbal::ClientProxy prints " no headers. reading."
· When reading a request, if we're not buffering to disk or we're no
longer reading, as we disable reads, Perlbal::ClientProxy prints "
disabling reads."
· As we're reading, Perlbal::ClientProxy prints " reading $read_size
bytes (VALUE bytes remain)", where "VALUE bytes remain" can be
<undef>
· After each read, Perlbal::ClientProxy prints " read $len bytes"
· After we finished reading the request, Perlbal::ClientProxy prints
" done_reading = $done_reading, backend = BACKEND", where
"BACKEND" can be "undef"
· When we send the headers to the backend and it responds before
we're done reading from the client, further reads from the client
are discarded; in this situation Perlbal::ClientProxy prints "
already responded.". If the client continues to send data,
Perlbal::ClientProxy prints " already responded [2]." and then
gives up on reading
· After reading, and having a backend available where we can write
to, just before we do, Perlbal::ClientProxy prints " got a
backend. sending write to it."
· After reading, if there's no backend available,
Perlbal::ClientProxy prints " no backend. read_ahead =
$self-"{read_ahead}.>
· If we know we've already started spooling a file to disk and we're
about to continue doing so, Perlbal::ClientProxy prints " bureason
= $self-"{bureason}>
· If a backend wasn't available and we're about to request one,
Perlbal::ClientProxy prints " finally requesting a backend"
· When we're trying to read headers and the client has disconnected,
Perlbal::Socket prints " client disconnected"
· If we need to remove a trailing "\r\n" from the headers,
Perlbal::Socket prints " throwing away leading \r\n"
· If we've read a packet with headers and by the end of it we can't
find the end of them, Perlbal::Socket prints " can't find end of
headers"
· Once we've read some headers, Perlbal::Socket prints " pre-parsed
headers: [$hstr]"
· After reading headers, if there's additional content that we've
read, we push it back; when we do so, Perlbal::Socket prints "
pushing back $len bytes after header"
· If we got bogus headers, and right before we close the connection
due to a parsing failure, Perlbal::Socket prints " bogus headers"
· If we got valid headers, Perlbal::Socket prints " got valid
headers"
· If we're reading buffered data from a client, Perlbal::Socket
prints "draining readbuf from $self to $dest: [$$bref]"
Debug level 4
By setting the debug level to 4 you get all the messages from levels 1
to 3.
Plus, "write" is redefined so that whenever "write" is called it first
prints "write($self, <$clen>"$content") from ($pkg, $filename, $line)".
PERLBAL_DEBUG = 4
SEE ALSO
Perlbal::Manual::Configuration, Perlbal::Manual::Management.
perl v5.14.2 2011-01-23 Perlbal::Manual::Debugging(3)
