Announce: perlbal-1.2

Brad Fitzpatrick brad at
Mon Mar 7 16:47:12 PST 2005


New release of Perlbal.  (shit, it's been like 5 months!)

We've been busy, though.  Changelog below.



  This provides a fast implementation of header parsing which is the
  main CPU hog in Perlbal.

  To enable it, on the management port, or in your config file:

     xs enable headers

  You can turn it on/off at runtime to compare CPU usage.


  Mark Smith <junior at> is the main hacker on Perlbal nowadays,
  and he's solely responsible for the new XS Header parsing code.  I'm
  mostly the suit (well, t-shirt) that tells him what to do.

Changelog since 1.0.1:

    -- add new stats command 'nodes' that shows information on each node that we've
       been connecting to -- last connect time, last attempt time, a breakdown of
       the last 500 status codes returned, etc

    -- add ability to use new Danga::Socket profiling; 'profile on', 'profile data'
       to see the info so far, and 'profile off' to disable it

    -- graceful shutdown now flags sockets that are busy to die so they die when
       they're done with their current connection

    -- sockets in persist_wait now get closed immediately during a graceful shutdown

    -- fix handling of OPTIONS responses; used to do its own state clearing but
       it now uses the next_request method as it should

    -- fix bug with determination of keep-alive in http 1.1 case specifying
       a connection: close header

    -- added 'uptime' management command to track how long Perlbal has been up

    -- new config commands: HEADER INSERT <svc> <header>: <value> and HEADER
       REMOVE <svc> <header> which will insert and remove headers from user
       requests before they're sent to backend proxy nodes.

    -- add dependency to Net::Netmask; now you can specify trusted_upstream_proxies
       on a service (SET service.trusted_upstream_proxies =, etc)
       which will allow requests from that range to set X-Forwarded-For, X-Host,
       and X-Forwarded-Host headers.

    -- fixed a bug that caused connections to hang when the backend responded
       before the user was done sending data

    -- reset some variables that weren't being reset: read_buf, read_ahead, read_size

    -- "proc" management command shows user and system CPU usage for Perlbal
       this run, as well as a delta since the last time you ran "proc"

    -- added Perlbal::XS interface for modules to use; also 'xs' management
       command to see the status of XS modules

    -- bug in PalImg caused crash on files with no length (or when another
       error occurs that causes no data to be sent to new_gif_palette function)

    -- ReproxyManager would sometimes let closed backends back into the pool
       and hand them off to clients, fixed to check for that

    -- new policy: you don't muck around with the internals of other classes.
       notably, clients don't change the internals of a backend and backends
       don't change the internals of a client.  this was causing all sorts of
       problems because nobody was cleaning up properly.  (especially with regard
       to "who is my backend's client" type questions.)

    -- fixed up code that did its own keep-alive checks to use the HTTPHeaders
       functions so that in the future every part of the code stays up to date

    -- Perlbal::Socket now has the option to keep track of all objects that
       are created.  new command to management interface 'leaks' will show
       all objects currently in memory.  turn this functionality on by enabling
       the TRACK_OBJECTS constant in Perlbal::Socket.

    -- split keep-alive logic into request and response methods and cleared
       up how that works

    -- rewrote reproxy URI support.  new class Perlbal::ReproxyManager does all
       of the work relating to reproxies.  it's basically a service class but
       stripped down and dealing with single endpoints instead of pools.  much
       much much more robust under heavy load.  (Junior, Brad)

    -- now that we support persistent connections, the 'queues' command didn't
       have an accurate time; added ClientProxy member last_request_time so
       we can accurately tell how long requests have been waiting for

    -- Danga::Socket got an overhaul; close and steal_socket now share a lot
       of code by calling _cleanup.  some more paranoia on making sure the
       object isn't already closed when we try to do things.

    -- lots more paranoia in close events and event_err handling for backends

    -- added tracking mode for helping look for leaked objects; records a
       backtrace of every object created.  "server track_obj = 0/1" to enable
       or disable it, and then "tracking" in a management interface to see.

    -- made Perlbal::objctor/objdtor take an object as their first parameter.
       much faster than using caller().

    -- fix Highpri plugin to not check hosts for high priority values when
       the host isn't defined

    -- made Palimg plugin far more paranoid about errors, and also uses new
       ClientHTTPBase scratch area for keeping track of data instead of using
       headers (which are generally slower)

    -- fixed bug in HTTPHeaders that set_version would inadvertently
       run into when used on a header created through new_response

    -- ClientProxy class now supports persistence; set persist_client on
       the proxy service in order to enable it.

    -- Palimg plugin now supports fallback to web server mode if the
       requested URI doesn't fit our desired pattern

    -- did some cleanup; made a bunch of HTTPHeaders accesses use the
       accessor methods instead of referencing into the object's private
       store of data

    -- fixed a crash caused by calling getsockname/getpeername on sockets
       that have been undefined after having been stolen during an internal
       redirect to another webserver

    -- fixed _simple_response to not return a body if we're serving
       to a HEAD request

    -- bug fix: don't send Not-Modified responses to requests for dynamic
       directory listings.  it was messing up persistent connections
       since the directory serving code didn't get passed down whether we
       were sending a body or not.  and not modifies on directories are hard:
       modify time isn't altogether useful.  (file sizes could change)

       this still does not-modifieds on indirect index.html directory
       requests, because _serve_request ends up eventually calling
       _serve_request on a different URI.  (brad)

    -- added BSD::Resource as dependency to Makefile.PL (brad)

    -- fixed 304 Not Modified responses to not send Content-Length
       and Content-Type headers.  (jr)

- Brad

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