speed up detection of changed databases

plugins/localdump/couchdb2.sh

@@ -27,6 +27,7 @@
 # 2022-10-07  ah     v1.8  unescape regex with space to prevent "grep: warning: stray \ before white space"
 # 2023-06-06  ah     v1.9  show a warning if the sequence id was not fetched
 # 2023-06-12  ah     v1.10 skip couchdb dump if no sequence id was detected (=db deleted since fetching list of all dbs)
+# 2023-06-26  ah     v1.11 speed up detection of changed databases
 # ================================================================================
 
 if [ -z "$BACKUP_TARGETDIR" ]; then
@@ -85,6 +86,55 @@ function _getDbSeq(){
 }
 
 
+
+# active curl prozesses
+function curlCount(){
+  ps -ef | grep -v grep | grep "curl" | wc -l
+}
+
+# wait until min N curl prozesses exist
+function wait4curlcount(){
+  typeset -i local iContinue
+  typeset -i local iCount
+
+  iContinue=${1:-0}
+  iCount=$( curlCount )
+
+  test $iCount -gt $iContinue && wait4curlcount $iContinue
+}
+
+function reqCombined(){
+  typeset -i local iChunksize; iChunksize=$1
+  typeset -i local iParallel;  iParallel=$2
+
+  typeset -i iCounter=0
+  cmdline=
+
+  for mydb in $dblist
+  do 
+
+      iCounter+=1
+      test -n "$cmdline" && cmdline+=" -: "
+      cmdline+="${COUCH_URL}${mydb} "
+
+      if [ $iCounter -ge $iChunksize ]; then
+
+          curl -s $cmdline &
+          # warte, solange Zahl curl Prozesse kleiner Maximum
+          wait4curlcount $iParallel
+
+          iCounter=0
+          cmdline=
+      fi
+
+  done
+  test -n "${cmdline}" && curl -s $cmdline &
+
+  wait4curlcount 0
+}
+
+
+
 # ---------- CONFIG/ INSTANCES
 
 # get valid configured instances
@@ -168,15 +218,13 @@ function _doBackupOfSingleInstance(){
   echo
 
   # get a list of current databases
-  dblist=/tmp/couch_list_${COUCHDB_INSTANCE}.txt
-  _getDblist > "$dblist"
-  ls -l "$dblist"
+  dblist=$( _getDblist )
 
   # detect deleted databases: 
   for dumpfile in $( find "${ARCHIVE_DIR}/${COUCHDB_INSTANCE}/" -maxdepth 1 -type f -name "*.couchdbdump.gz" )
   do
       dbname=$( basename $dumpfile | sed "s#\.couchdbdump\.gz##g" )
-      if ! grep "^${dbname}" "$dblist" >/dev/null; then
+      if ! grep "^${dbname}" <<< "$dblist" >/dev/null; then
               SEQFILE=${ARCHIVE_DIR}/${COUCHDB_INSTANCE}/seq/__seq__${dbname}
               SECURITYFILE=${ARCHIVE_DIR}/${COUCHDB_INSTANCE}/security/__security__${dbname}.json
               echo "DELETED $dbname ... $( ls -l ${dumpfile} | cut -f 5- -d ' ' )"
@@ -188,7 +236,7 @@ function _doBackupOfSingleInstance(){
   # done | tee /tmp/couch_archive_${COUCHDB_INSTANCE}.txt
   echo
 
-  typeset -i iDbTotal=$( cat "$dblist" | wc -l )
+  typeset -i iDbTotal=$( echo "$dblist" | wc -l )
   typeset -i iDb=0
   typeset -i iDbCount=0
 
@@ -198,16 +246,36 @@ function _doBackupOfSingleInstance(){
   echo "      ARCHIVE ${ARCHIVE_DIR}/${COUCHDB_INSTANCE}"
   echo
 
-  for dbname in $( cat "$dblist" )
+  local iChunksize=100
+  local iParallel=10
+  echo "--- $( date ) - Get database meta infos ... max $iParallel parralel curl requests sending $iChunksize database urls per connection"
+  seq=$( reqCombined 100 6 | jq -r ' [ .db_name, .update_seq ] | @csv ' | tr -d '"')
+
+  declare -A aSeq
+
+  echo "--- $( date ) - reading sequence ids..."
+  for line in $( echo "$seq" )
   do
-    iDb=$iDb+1
+    IFS="," read -r db seqvalue <<< "$line"
+    IFS="-" read -r seqid dummy <<< "$seqvalue"
+    # seqid=$( echo $seqvalue | cut -f 1 -d '-')
+    aSeq+=([$db]=$seqid)
+  done
+
+
+
+  for dbname in $( echo "$dblist" )
+  do
+    iDb+=1
     echo -n "----- $(date) ${COUCHDB_INSTANCE} -- $iDb of $iDbTotal - ${dbname} - "
     OUTFILE=${BACKUP_TARGETDIR}/${COUCHDB_INSTANCE}/$(get_outfile "${dbname}").couchdbdump
     ARCHIVFILE=${ARCHIVE_DIR}/${COUCHDB_INSTANCE}/${dbname}.couchdbdump.gz
     SEQFILE=${ARCHIVE_DIR}/${COUCHDB_INSTANCE}/seq/__seq__${dbname}
     SECURITYFILE=${ARCHIVE_DIR}/${COUCHDB_INSTANCE}/security/__security__${dbname}.json
 
-    sSequenceCurrent=$(_getDbSeq "${dbname}")
+    # sSequenceCurrent=$(_getDbSeq "${dbname}")
+    sSequenceCurrent="${aSeq[$dbname]}"
+
     sSequenceLast=$(cat "${SEQFILE}" 2>/dev/null | cut -f 1 -d '-')
 #    sSequenceLast=`cat ${SEQFILE} 2>/dev/null | tr -d '\n'`
 
@@ -231,6 +299,7 @@ function _doBackupOfSingleInstance(){
         echo "update_seq --+-- current [${sSequenceCurrent}]" 
         echo "             +-- backup  [${sSequenceLast}]"
         echo -n "Need to backup ... "
+
         couchbackup --db "${dbname}" >"${OUTFILE}".progress 2>/dev/null && mv "${OUTFILE}".progress "${OUTFILE}"
         fetchrc
 
@@ -254,7 +323,6 @@ function _doBackupOfSingleInstance(){
       fi # if [ -z "$sSequenceCurrent" ]; then
     fi # if [ "${sSequenceCurrent}" = "${sSequenceLast}" ] ...
   done
-  rm -f "$dblist"
   echo "__DB__$SERVICENAME backup INFO: ${COUCHDB_INSTANCE} - backed up $iDbCount dbs of $iDbTotal total"
 
 }