5.4 Server

The SERVER activity manage local cache integrity and exchange files with other MEDIATEX’s SERVERs. CLIENT (see Client) may ask it to updates the ~mdtx/md5sums/mdtx-COLL.md5 (see mdtxCOLL.md5) file that gives the local cache’s status.

The SERVER activity is divided into 7 process:

Flood diagram:

• Events in

  # nohup mediatexd

  # kill -s TERM PID

  # kill -s HUP PID

  from init.d (see init.d): standard UNIX process management (HUP signal for reload...).

  [save]

  from misc (see misc): serialize the last cache status into a file.

  [extract]

  [notify]

  from CLIENT respectively to extract (see extract), notify (see notify): ask server to extract or notify locally available archive contents to other servers.

  [quick-scan]

  [scan]

  from CLIENT: ask server to check recorded local supplies are still available from the cache and match recorded size ([quick-scan]) or both recorded md5sum and size ([scan]). Next, scan the cache directory and remind new local-supplies founded, or remove files if they do not match an extraction rule.

  [trim]

  from CLIENT: remove form cache all files that are safe and extractable from a containers available into the cache.

  [clean]

  from CLIENT: remove form cache all files that are safe and extractable from supports locally available.

  [purge]

  from CLIENT: remove form cache all files that are safe.

  [status]

  from CLIENT: ask server print into the logs its memory status.

  <cgiSrv-query>

  from cgiClient (see cgiClient) to cgiServer (see cgiServer): receive a socket query asking for an archive.

  <have>

  from supp (see supp) to have (see have): receive a socket query providing archives from a support.

  <upload>

  from misc (see misc) to cache (see cache): receive a socket query providing an archive and asking to handle it into the cache.

  <notify>

  from a remote SERVER to notify (see notify): receive a socket query providing remote cache content index.

• Processing
  • Serialise cache index into ~mdtx/md5sums/mdtx-COLL.md5 (see mdtxCOLL.md5), on [extract] query. Remote supplies and demands are now readable by CLIENT, or on next SERVER (see Server) start-up.
  • Re-index the cache when receiving HUP signal:
    • wait until all threads end,
    • lock concurent threads setup
    • serialise cache index into ~mdtx/md5sums/mdtx-COLL.md5 (see mdtxCOLL.md5),
    • free all memory used,
    • parse /etc/mediatex/mdtx.conf (see mdtx.conf) file configuration,
    • parse ~mdtx/md5sums/mdtx-COLL.md5 (see mdtxCOLL.md5),
    • scan the cache directory
    • unlock concurent threads setup
• Events out

  $ mediatex adm bind

  $ mediatex adm unbind

  $ mediatex adm get path as coll on path

  to misc (see misc): tells client to make operations that needs privileges, like binding directories into the chroot jail or using collection account to retrieve archives remotely.

  $ mediatex adm mount iso on path

  $ mediatex adm umount path

  from extract (see extract) to supp (see supp): tel client to mount supports as it need root privileges.

  <notify>

  from notify (see notify) to a remote SERVER: send a socket query providing local cache content index.

  $ /usr/share/mediatex/scripts/deliver.sh

  $ /usr/share/mediatex/scripts/audit.sh

  from delivering (see delivering) to deliver (see deliver) or audit (see audit): respectively notify archive availability to USER or audit an archive.

• Data in

  /etc/mediatex/mdtx.conf (see mdtx.conf)

  ~mdtx/git/mdtx/supports.txt (see supports.txt)

  /etc/mediatex/mdtx-COLL/servers.txt (see servers.txt)

  /etc/mediatex/mdtx-COLL/extractXXX.txt (see extract.txt)

• Data in/out

  ~mdtx/md5sums/mdtx-COLL.md5 (see mdtxCOLL.md5)

Return codes on <socket> messages:

• status (X--)

  1-- …

  negative reply

  2-- …

  ok

  3-- …

  bad request

  4-- …

  internal error

• Generic messages (-0-)

  301 message parser error

  302 message without collection

  303 message from server '%s' not registered into %s collection

  304 message contains a record not related to author %s but %s

  305 unknown message type: %s

  400 internal error

  401 fails to read message

  402 fails to load %s collection's serverTree

  403 fails to get localhost

  404 fails to load %s collection's cache

• uploadServer (see uploadServer) messages (-1-)

  210 ok

  310 empty message

  332 message do not provide a final supply %s

  313 already exists %s:%lli

• cgiServer (see cgiServer) messages (-2-)

  120 not found %s:%lli

  220 ok %s/%s

  221 ok

  320 empty message

• have (see have) messages (-3-)

  230 ok

  330 empty message

  331 message do not provide a final supply %s

• notify (see notify) messages (-4-)

  240 ok

Code:

src/server/threads.c

src/mediatexd.c