EXTTODO by Claudio Jeker and Andre Oppermann (c) 1998,1999,2000,2001,2002 Internet Business Solutions Ltd. The EXTTODO patch is a part of the qmail-ldap patch. This patches for qmail come with NO WARRANTY. These patches are under the BSD license. RELEASE: 5. Jan. 2003 EXTTODO: ====================== TOC: WHAT DOES IT DO INSTALL CONFIG FILES SETUP BIG PICTURE NEWS: This is the first release of the EXTTODO patch. ================================================================================ WHAT DOES IT DO The exttodo patch addresses a problem known as the silly qmail (queue) problem. This problem is found only on system with high injection rates. qmail with a big local and remote concurrency could deliver a tremendous amount of messages but normally this can not be achieved because qmail-send becomes a bottleneck on those high volumes servers. qmail-send preprocesses all new messages before distributing them for local or remote delivering. In one run qmail-send does one todo run but has the ability to close multiple jobs. Because of this layout qmail-send can not feed all the new available (local/remote) delivery slots and therefor it is not possible to achieve the maximum throughput. This would be a minor problem if one qmail-send run could be done in extreme short time but because of many file system calls (fsync and (un)link) a todo run is expensive and throttles the throughput. The exttodo patch tries to solve the problem by moving the todo routine into an external program. This reduces the run time in qmail-send. exttodo adds a new program to qmail called qmail-todo. qmail-todo prepares incoming messages for local and remote delivering (by creating info/ local/ and remote/ and removing todo/). See also INTERNALS. As next qmail-todo transmits the to qmail-send which will add this message into the priority queue which schedules the message for delivery. INSTALL To enable the exttodo patch you need to define EXTERNAL_TODO while compiling qmail(-ldap) this can be done with the -D flag of cc (e.g. cc -DEXTERNAL_TODO). NOTE: the exttodo patch can also be used on qmail systems without the qmail-ldap patch. ================================================================================ CONFIG FILES No additional control files are used or needed. ================================================================================ SETUP qmail-todo will be started by qmail-start and therefor no additional setup is needed. To verify that exttodo is running just check if qmail-todo is running. ================================================================================ BIG PICTURE +-------+ +-------+ | clean | | clean | +--0-1--+ +--0-1--+ +-----------+ trigger ^ | ^ | +->0,1 lspawn | | | v | v / +-----------+ +-------+ v +--2-3--+ +--5-6--+ / | | | | 0<--7 1,2<-+ | queue |--+--| todo | | send | | | | | 1-->8 3,4<-+ +-------+ +-------+ +---0---+ \ | \ +-----------+ v +->0,1 rspwan | +---0---+ +-----------+ | logger| +-------+ Communication between qmail-send and qmail-todo todo -> send: D[LRB]\0 Start delivery for new message with id . the character L, R or B defines the type of delivery, local, remote or both respectively. L\0 Dump string to the logger without adding additional \n or similar. send -> todo: H Got a SIGHUP reread ~/control/locals and ~/control/virtualdomains X Quit ASAP. qmail-todo sends "\0" terminated messages whereas qmail-send just send one character to qmail-todo. EXTTODO by Claudio Jeker and Andre Oppermann (c) 1998,1999,2000,2001,2002 Internet Business Solutions Ltd. The EXTTODO patch is a part of the qmail-ldap patch. This patches for qmail come with NO WARRANTY. These patches are under the BSD license. RELEASE: 5. Jan. 2003 EXTTODO: ====================== TOC: WHAT DOES IT DO INSTALL CONFIG FILES SETUP BIG PICTURE NEWS: This is the first release of the EXTTODO patch. ================================================================================ WHAT DOES IT DO The exttodo patch addresses a problem known as the silly qmail (queue) problem. This problem is found only on system with high injection rates. qmail with a big local and remote concurrency could deliver a tremendous amount of messages but normally this can not be achieved because qmail-send becomes a bottleneck on those high volumes servers. qmail-send preprocesses all new messages before distributing them for local or remote delivering. In one run qmail-send does one todo run but has the ability to close multiple jobs. Because of this layout qmail-send can not feed all the new available (local/remote) delivery slots and therefor it is not possible to achieve the maximum throughput. This would be a minor problem if one qmail-send run could be done in extreme short time but because of many file system calls (fsync and (un)link) a todo run is expensive and throttles the throughput. The exttodo patch tries to solve the problem by moving the todo routine into an external program. This reduces the run time in qmail-send. exttodo adds a new program to qmail called qmail-todo. qmail-todo prepares incoming messages for local and remote delivering (by creating info/ local/ and remote/ and removing todo/). See also INTERNALS. As next qmail-todo transmits the to qmail-send which will add this message into the priority queue which schedules the message for delivery. INSTALL To enable the exttodo patch you need to define EXTERNAL_TODO while compiling qmail(-ldap) this can be done with the -D flag of cc (e.g. cc -DEXTERNAL_TODO). NOTE: the exttodo patch can also be used on qmail systems without the qmail-ldap patch. ================================================================================ CONFIG FILES No additional control files are used or needed. ================================================================================ SETUP qmail-todo will be started by qmail-start and therefor no additional setup is needed. To verify that exttodo is running just check if qmail-todo is running. ================================================================================ BIG PICTURE +-------+ +-------+ | clean | | clean | +--0-1--+ +--0-1--+ +-----------+ trigger ^ | ^ | +->0,1 lspawn | | | v | v / +-----------+ +-------+ v +--2-3--+ +--5-6--+ / | | | | 0<--7 1,2<-+ | queue |--+--| todo | | send | | | | | 1-->8 3,4<-+ +-------+ +-------+ +---0---+ \ | \ +-----------+ v +->0,1 rspwan | +---0---+ +-----------+ | logger| +-------+ Communication between qmail-send and qmail-todo todo -> send: D[LRB]\0 Start delivery for new message with id . the character L, R or B defines the type of delivery, local, remote or both respectively. L\0 Dump string to the logger without adding additional \n or similar. send -> todo: H Got a SIGHUP reread ~/control/locals and ~/control/virtualdomains X Quit ASAP. qmail-todo sends "\0" terminated messages whereas qmail-send just send one character to qmail-todo.