diff --git a/python/check_os.sh b/python/check_os.sh
index 5f8c622d062c64a8e1e7032e1968644dae5450d6..a47c531c238ff92c0fbf61c74353540cef794911 100644
--- a/python/check_os.sh
+++ b/python/check_os.sh
@@ -15,40 +15,66 @@ if [ x"$filter_os_disk" = x ];then
 fi
 
 mysql_client="mysql -h${host}  -P${port}  -u${user}  -p${password}"
+RETRIES=3
+TIMEOUT=10
+snmpwalk="/usr/bin/snmpwalk -r $RETRIES -t $TIMEOUT"
+snmpget="/usr/bin/snmpget -r $RETRIES -t $TIMEOUT"
+snmpdf="/usr/bin/snmpdf -r $RETRIES -t $TIMEOUT"
 
-hostname=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}   SNMPv2-MIB::sysName.0|awk '{print $NF}'`
-if [ "$hostname" != "" ];then
-    kernel=`snmpwalk -v1 -c ${community}  ${ip}  SNMPv2-MIB::sysDescr.0|awk '{print $4 " " $6 " " $15}'`
-    system_date=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}   HOST-RESOURCES-MIB::hrSystemDate.0|cut -d '=' -f2|cut -d ' ' -f3`
-    system_uptime=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}   HOST-RESOURCES-MIB::hrSystemUptime.0|cut -d ')' -f2`
-    process=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}   HOST-RESOURCES-MIB::hrSystemProcesses.0|cut -d ' ' -f4`
+snmpdata=$($snmpget -v1 -c ${community} ${ip} SNMPv2-MIB::sysName.0 \
+    SNMPv2-MIB::sysDescr.0 \
+    HOST-RESOURCES-MIB::hrSystemDate.0 \
+    HOST-RESOURCES-MIB::hrSystemUptime.0 \
+    HOST-RESOURCES-MIB::hrSystemProcesses.0 \
+    UCD-SNMP-MIB::laLoad.1 \
+    UCD-SNMP-MIB::laLoad.2 \
+    UCD-SNMP-MIB::laLoad.3 \
+    UCD-SNMP-MIB::ssCpuUser.0 \
+    UCD-SNMP-MIB::ssCpuSystem.0 \
+    UCD-SNMP-MIB::ssCpuIdle.0 \
+    UCD-SNMP-MIB::memTotalSwap.0 \
+    UCD-SNMP-MIB::memAvailSwap.0 \
+    UCD-SNMP-MIB::memTotalReal.0 \
+    UCD-SNMP-MIB::memAvailReal.0 \
+    UCD-SNMP-MIB::memTotalFree.0 \
+    UCD-SNMP-MIB::memShared.0 \
+    UCD-SNMP-MIB::memBuffer.0 \
+    UCD-SNMP-MIB::memCached.0 \
+    2>/dev/null)
 
-    load_1=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}   UCD-SNMP-MIB::laLoad.1|awk '{print $NF}'`
-    load_5=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}   UCD-SNMP-MIB::laLoad.2|awk '{print $NF}'`
-    load_15=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}   UCD-SNMP-MIB::laLoad.3|awk '{print $NF}'`
+if [ "$snmpdata" != "" ]; then
+    hostname=`echo "$snmpdata" | grep SNMPv2-MIB::sysName.0|awk '{print $NF}'`
+    kernel=`echo "$snmpdata" | grep SNMPv2-MIB::sysDescr.0|awk '{print $4 " " $6 " " $15}'`
+    system_date=`echo "$snmpdata" | grep HOST-RESOURCES-MIB::hrSystemDate.0|cut -d '=' -f2|cut -d ' ' -f3`
+    system_uptime=`echo "$snmpdata" | grep HOST-RESOURCES-MIB::hrSystemUptime.0|cut -d ')' -f2`
+    process=`echo "$snmpdata" | grep HOST-RESOURCES-MIB::hrSystemProcesses.0|cut -d ' ' -f4`
 
-    cpu_user_time=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::ssCpuUser.0 |awk '{print $NF}'`
-    cpu_system_time=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::ssCpuSystem.0 |awk '{print $NF}'`
-    cpu_idle_time=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::ssCpuIdle.0 |awk '{print $NF}'`
+    load_1=`echo "$snmpdata" | grep UCD-SNMP-MIB::laLoad.1|awk '{print $NF}'`
+    load_5=`echo "$snmpdata" | grep UCD-SNMP-MIB::laLoad.2|awk '{print $NF}'`
+    load_15=`echo "$snmpdata" | grep UCD-SNMP-MIB::laLoad.3|awk '{print $NF}'`
 
-    swap_total=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::memTotalSwap.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
-    swap_avail=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::memAvailSwap.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
-    mem_total=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::memTotalReal.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
-    mem_used=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::memAvailReal.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
-    mem_free=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::memTotalFree.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
-    mem_shared=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::memShared.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
-    mem_buffered=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::memBuffer.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
-    mem_cached=`/usr/bin/snmpwalk -v1 -c ${community}  ${ip}  UCD-SNMP-MIB::memCached.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
-    mem_usage_rate=`/usr/bin/snmpdf -v1 -c ${community}  ${ip}  |grep "Physical"|awk '{print $6}'`
-    mem_available=$[$mem_free+$mem_buffered+$mem_cached]
+    cpu_user_time=`echo "$snmpdata" | grep UCD-SNMP-MIB::ssCpuUser.0 |awk '{print $NF}'`
+    cpu_system_time=`echo "$snmpdata" | grep UCD-SNMP-MIB::ssCpuSystem.0 |awk '{print $NF}'`
+    cpu_idle_time=`echo "$snmpdata" | grep UCD-SNMP-MIB::ssCpuIdle.0 |awk '{print $NF}'`
+
+    swap_total=`echo "$snmpdata" | grep UCD-SNMP-MIB::memTotalSwap.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
+    swap_avail=`echo "$snmpdata" | grep UCD-SNMP-MIB::memAvailSwap.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
+    mem_total=`echo "$snmpdata" | grep UCD-SNMP-MIB::memTotalReal.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
+    mem_used=`echo "$snmpdata" | grep UCD-SNMP-MIB::memAvailReal.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
+    mem_free=`echo "$snmpdata" | grep UCD-SNMP-MIB::memTotalFree.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
+    mem_shared=`echo "$snmpdata" | grep UCD-SNMP-MIB::memShared.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
+    mem_buffered=`echo "$snmpdata" | grep UCD-SNMP-MIB::memBuffer.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
+    mem_cached=`echo "$snmpdata" | grep UCD-SNMP-MIB::memCached.0 |cut -d= -f2 |awk -F ' ' '{print $2}'`
 
+    mem_usage_rate=`$snmpdf -v1 -c ${community}  ${ip}  |grep "Physical"|awk '{print $6}'`
+    mem_available=$[$mem_free+$mem_buffered+$mem_cached]
 
    #disk usage
    IFS=$'\n'
-   disk_all=`/usr/bin/snmpdf -v1 -c  ${community} ${ip} |grep -E "/"|grep -vE "/dev|/boot" |grep -vE "$filter_os_disk"`
+   disk_all=`$snmpdf -v1 -c  ${community} ${ip} |grep -E "/"|grep -vE "/dev|/boot" |grep -vE "$filter_os_disk"`
    for line in $disk_all
    do
-      IFS=' ' 
+      IFS=' '
       mounted=`echo $line|awk -F ' ' '{print $1}' `
       total_size=`echo $line|awk -F ' ' '{print $2}' `
       used_size=`echo $line|awk -F ' ' '{print $3}' `
@@ -56,22 +82,22 @@ if [ "$hostname" != "" ];then
       used_rate=`echo $line|awk -F ' ' '{print $5}' `
       $mysql_client -N -e "insert  into $dbname.os_disk(ip,tags,mounted,total_size,used_size,avail_size,used_rate) values('${ip}','${tags}','${mounted}','${total_size}','${used_size}','${avail_size}','${used_rate}')"
    done
-   
+
    #disk io
-   IFS=$'\n'
    disk_io_reads_total=0
    disk_io_writes_total=0
-   fdisk_io_string=`/usr/bin/snmpwalk -v1 -c ${community} ${ip}  UCD-DISKIO-MIB::diskIODevice |grep -ivE "ram|loop|md"`
+   fdisk_io_string=`$snmpwalk -v1 -c ${community} ${ip}  UCD-DISKIO-MIB::diskIODevice |grep -ivE "ram|loop|md"`
+   IFS=$'\n'
    for line in $fdisk_io_string
    do
       IFS=' '
       fdisk=`echo $line|awk -F ' ' '{print $4}'`
       fdisk_id=`echo $line|awk -F ' ' '{print $1}'|awk -F '.' '{print $2}'`
-      disk_io_reads_1=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} UCD-DISKIO-MIB::diskIOReads.$fdisk_id|awk '{print $NF}'`
-      disk_io_writes_1=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} UCD-DISKIO-MIB::diskIOWrites.$fdisk_id|awk '{print $NF}'`
+      disk_io_reads_1=`$snmpwalk -v1 -c ${community} ${ip} UCD-DISKIO-MIB::diskIOReads.$fdisk_id|awk '{print $NF}'`
+      disk_io_writes_1=`$snmpwalk -v1 -c ${community} ${ip} UCD-DISKIO-MIB::diskIOWrites.$fdisk_id|awk '{print $NF}'`
       sleep 1
-      disk_io_reads_2=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} UCD-DISKIO-MIB::diskIOReads.$fdisk_id|awk '{print $NF}'`
-      disk_io_writes_2=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} UCD-DISKIO-MIB::diskIOWrites.$fdisk_id|awk '{print $NF}'`
+      disk_io_reads_2=`$snmpwalk -v1 -c ${community} ${ip} UCD-DISKIO-MIB::diskIOReads.$fdisk_id|awk '{print $NF}'`
+      disk_io_writes_2=`$snmpwalk -v1 -c ${community} ${ip} UCD-DISKIO-MIB::diskIOWrites.$fdisk_id|awk '{print $NF}'`
       disk_io_reads=$(($disk_io_reads_2-$disk_io_reads_1))
       disk_io_writes=$(($disk_io_writes_2-$disk_io_writes_1))
       #disk_io_reads=`expr $disk_io_reads / 3`
@@ -83,20 +109,20 @@ if [ "$hostname" != "" ];then
 
 
    #net
-   IFS=$'\n'
    net_in_bytes_total=0
    net_out_bytes_total=0
-   net_descr_string=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifDescr`
+   net_descr_string=`$snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifDescr`
+   IFS=$'\n'
    for line in $net_descr_string
    do
        IFS=' '
        net_descr=`echo $line|awk -F '=' '{print $2}' |awk -F ': ' '{print $2}'`
        net_descr_id=`echo $line|awk -F ' ' '{print $1}'|awk -F '.' '{print $2}'`
-       in_bytes_1=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifInOctets.$net_descr_id|awk '{print $NF}'`
-       out_bytes_1=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifOutOctets.$net_descr_id|awk '{print $NF}'`
+       in_bytes_1=`$snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifInOctets.$net_descr_id|awk '{print $NF}'`
+       out_bytes_1=`$snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifOutOctets.$net_descr_id|awk '{print $NF}'`
        sleep 1
-       in_bytes_2=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifInOctets.$net_descr_id|awk '{print $NF}'`
-       out_bytes_2=`/usr/bin/snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifOutOctets.$net_descr_id|awk '{print $NF}'`
+       in_bytes_2=`$snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifInOctets.$net_descr_id|awk '{print $NF}'`
+       out_bytes_2=`$snmpwalk -v1 -c ${community} ${ip} IF-MIB::ifOutOctets.$net_descr_id|awk '{print $NF}'`
        in_bytes=$(($in_bytes_2-$in_bytes_1))
        out_bytes=$(($out_bytes_2-$out_bytes_1))
        #in_bytes=`expr $in_bytes / 3`