diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/doc-docbook/spec.xfpt | 26 | ||||
| -rw-r--r-- | doc/doc-txt/ChangeLog | 24 |
2 files changed, 41 insertions, 9 deletions
diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 4a044bb11..43ce00cdc 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -953,7 +953,7 @@ User filters are run as part of the routing process, described below. .cindex "exim_msgdate" Every message handled by Exim is given a &'message id'& which is sixteen characters long. It is divided into three parts, separated by hyphens, for -example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits, +example &`16VDhn-000000001bo-D342`&. Each part is a sequence of letters and digits, normally encoding numbers in base 62. However, in the Darwin operating system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36 (avoiding the use of lower case letters) is used instead, because the message @@ -974,21 +974,29 @@ started to be received, to a granularity of one second. That is, this field contains the number of seconds since the start of the epoch (the normal Unix way of representing the date and time of day). .next -After the first hyphen, the next six characters are the id of the process that -received the message. +After the first hyphen, the next +.new +eleven +.wen +characters are the id of the process that received the message. .next -There are two different possibilities for the final two characters: +.new +There are two different possibilities for the final four characters: .olist .oindex "&%localhost_number%&" If &%localhost_number%& is not set, this value is the fractional part of the -time of reception, normally in units of 1/2000 of a second, but for systems +time of reception, normally in units of +microseconds. +but for systems that must use base 36 instead of base 62 (because of case-insensitive file -systems), the units are 1/1000 of a second. +systems), the units are +2 us. .next -If &%localhost_number%& is set, it is multiplied by 200 (100) and added to -the fractional part of the time, which in this case is in units of 1/200 -(1/100) of a second. +If &%localhost_number%& is set, it is multiplied by +500000 (250000) and added to +the fractional part of the time, which in this case is in units of 2 us (4 us). .endlist +.wen .endlist After a message has been received, Exim waits for the clock to tick at the diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog index 09b4d3a60..9c073f3e0 100644 --- a/doc/doc-txt/ChangeLog +++ b/doc/doc-txt/ChangeLog @@ -133,6 +133,30 @@ JH/28 Bug 2996: Fix a crash in the smtp transport. When finding that the Pollution of logs was the major effect, as the other process delivered the message. Found and partly investigated by Graeme Fowler. +JH/29 Change format of the internal ID used for message identification. The old + version only supported 31 bits for a PID element; the new 64 (on systems + which can use Base-62 encoding, which is all currently supported ones + but not Darwin (MacOS) or Cygwin, which have case-insensitive filesystems + and must use Base-36). The new ID is 23 characters rather than 16, and is + visible in various places - notably logs, message headers, and spool file + names. Various of the ancillary utilities also have to know the format. + As well as the expanded PID portion, the sub-second part of the time + recorded in the ID is expanded to support finer precision. Theoretically + this permits a receive rate from a single comms channel of better than the + previous 2000/sec. + The major timestamp part of the ID is not changed; at 6 characters it is + usable until about year 3700. + Updating from previously releases is fully supported: old-format spool + files are still usable, and the utilities support both formats. New + message will use the new format. The one hints-DB file type which uses + message-IDs (the transport wait- DB) will be discarded if an old-format ID + is seen; new ones will be built with only new-format IDs. + Optionally, a utility can be used to convert spool files from old to new, + but this is only an efficiency measure not a requirement for operation + Downgrading from new to old requires running a provided utility, having + first stopped all operations. This will convert any spool files from new + back to old (losing time-precision and PID information) and remove any + wait- hints databases. Exim version 4.96 ----------------- |