syslog fix - Mailing list pgsql-hackers

Since logging with syslog is a documented feature, we need to fix it
anyway, IMHO. Here is a proposed fix for "too long message" problem of
syslog.

Included patches do followings:

o modifies write_syslog in utils/misc/trace.c

o if the message is too long (currently longer than 128 bytes), then
divides into smaller message segments. "128" would be probably too
small for some platforms, but I don't how long is the actual safe
limit of syslog messages on particular platform (seems 512 is safe on
Linux, for example).

o division of the message is carefully done so that it does not break
the word boundary.

o each message is prefixed with [logid-seq] where logid is incremented
at each write_syslog call, and seq is incremented at each syslog call
within a write_syslog call. This will prevent syslog to suppress
"same" messages.

o tested on Linux (RH4.2) and FreeBSD 4.0.

Comments are welcome....
--
Tatsuo Ishii

BTW, here are some examples from actual syslog messages:

May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-1] NOTICE:  QUERY DUMP:  { SEQSCAN :startup_cost 0.00 :total_cost
3.22:rows 122 :width 81 :state <> :qptargetlist ({ TARGETENTRY
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-2]  :resdom { RESDOM :resno 1 :restype 19 :restypmod -1 :resname
typname:reskey 0 :reskeyop 0 :ressortgroupref 0 :resjunk false }
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-3]  :expr { VAR :varno 1 :varattno 1 :vartype 19 :vartypmod -1
:varlevelsup0 :varnoold 1 :varoattno 1}} { TARGETENTRY :resdom {
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-4]  RESDOM :resno 2 :restype 23 :restypmod -1 :resname typowner
:reskey0 :reskeyop 0 :ressortgroupref 0 :resjunk false } :expr {
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-5]  VAR :varno 1 :varattno 2 :vartype 23 :vartypmod -1
:varlevelsup0 :varnoold 1 :varoattno 2}} { TARGETENTRY :resdom { RESDOM
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-6]  :resno 3 :restype 21 :restypmod -1 :resname typlen :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-7]  1 :varattno 3 :vartype 21 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 3}} { TARGETENTRY :resdom { RESDOM :resno 4
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-8]  :restype 21 :restypmod -1 :resname typprtlen :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-9]  :varattno 4 :vartype 21 :vartypmod -1  :varlevelsup 0 :varnoold
1:varoattno 4}} { TARGETENTRY :resdom { RESDOM :resno 5
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-10]  :restype 16 :restypmod -1 :resname typbyval :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-11]  :varattno 5 :vartype 16 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 5}} { TARGETENTRY :resdom { RESDOM :resno 6
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-12]  :restype 18 :restypmod -1 :resname typtype :reskey 0 :reskeyop
0:ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-13]  :varattno 6 :vartype 18 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 6}} { TARGETENTRY :resdom { RESDOM :resno 7
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-14]  :restype 16 :restypmod -1 :resname typisdefined :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-15]  :varattno 7 :vartype 16 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 7}} { TARGETENTRY :resdom { RESDOM :resno 8
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-16]  :restype 18 :restypmod -1 :resname typdelim :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-17]  :varattno 8 :vartype 18 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 8}} { TARGETENTRY :resdom { RESDOM :resno 9
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-18]  :restype 26 :restypmod -1 :resname typrelid :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-19]  :varattno 9 :vartype 26 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 9}} { TARGETENTRY :resdom { RESDOM :resno 10
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-20]  :restype 26 :restypmod -1 :resname typelem :reskey 0 :reskeyop
0:ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-21]  :varattno 10 :vartype 26 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 10}} { TARGETENTRY :resdom { RESDOM :resno 11
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-22]  :restype 24 :restypmod -1 :resname typinput :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-23]  :varattno 11 :vartype 24 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 11}} { TARGETENTRY :resdom { RESDOM :resno 12
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-24]  :restype 24 :restypmod -1 :resname typoutput :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-25]  :varattno 12 :vartype 24 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 12}} { TARGETENTRY :resdom { RESDOM :resno 13
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-26]  :restype 24 :restypmod -1 :resname typreceive :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-27]  :varattno 13 :vartype 24 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 13}} { TARGETENTRY :resdom { RESDOM :resno 14
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-28]  :restype 24 :restypmod -1 :resname typsend :reskey 0 :reskeyop
0:ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-29]  :varattno 14 :vartype 24 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 14}} { TARGETENTRY :resdom { RESDOM :resno 15
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-30]  :restype 18 :restypmod -1 :resname typalign :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-31]  :varattno 15 :vartype 18 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 15}} { TARGETENTRY :resdom { RESDOM :resno 16
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-32]  :restype 25 :restypmod -1 :resname typdefault :reskey 0
:reskeyop0 :ressortgroupref 0 :resjunk false } :expr { VAR :varno 1
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-33]  :varattno 16 :vartype 25 :vartypmod -1  :varlevelsup 0
:varnoold1 :varoattno 16}}) :qpqual <> :lefttree <> :righttree <>
 
May 23 10:58:51 srapc968-yotsuya postgres[9902]: [1-34]  :extprm () :locprm () :initplan <> :nprm 0  :scanrelid 1 }
May 23 10:58:51 srapc968-yotsuya postgres[9902]: NOTICE:  QUERY PLAN:  Seq Scan on pg_type  (cost=0.00..3.22 rows=122
width=81)