監控redis cluster 主從實例是否切換，切換前后對應關系

 

需求：編寫腳本實現對redis cluster 主從是否發生主從切換進行監控，若發生切換，輸出切換前后主從對應關系。

 

初始化對比文件,僅執行一次，后續不需要在執行，除非該文件不存在。

cmd="redis-cli -c -h $1 -p $2"
$cmd cluster nodes > cluster_nodes.txt
cat cluster_nodes.txt | awk -F[\ \@] '/master/{print $1,$2}' | sort -nk2 -t ':'  > master.txt
cat cluster_nodes.txt | awk -F[\ \@] '/slave/{print $2,$5}' | sort -nk1 -t ':'  > slave.txt
cat master.txt | while read m
do
        master_ip_port=`echo $m | awk '{print $2}'`
        master_tag=`echo $m | awk '{print $1}'`
        cat slave.txt | while read s
        do
                slave_ip_port=`echo $s | awk '{print $1}'`
                slave_tag=`echo $s | awk '{print $2}'`
                if [[ ${master_tag} == ${slave_tag} ]];then
                　　echo "${master_ip_port}->${slave_ip_port}" >> master_slave_map_old
                fi
        done
done

 

判斷是否發生切換，如果發生，輸出切換前后的對應關系

cmd="redis-cli -c -h $1 -p $2"
$cmd cluster nodes > cluster_nodes.txt
cat cluster_nodes.txt | awk -F[\ \@] '/master/{print $1,$2}' | sort -nk2 -t ':'  > master.txt
cat cluster_nodes.txt | awk -F[\ \@] '/slave/{print $2,$5}' | sort -nk1 -t ':'  > slave.txt
cat master.txt | while read m
do
        master_ip_port=`echo $m | awk '{print $2}'`
        master_tag=`echo $m | awk '{print $1}'`
        cat slave.txt | while read s
        do
                slave_ip_port=`echo $s | awk '{print $1}'`
                slave_tag=`echo $s | awk '{print $2}'`
                if [[ ${master_tag} == ${slave_tag} ]];then
                　　echo "${master_ip_port}->${slave_ip_port}" >> master_slave_map_new
                fi
        done
done


ports=($($cmd cluster nodes | awk -F[\ \:\@] '{print $3}' | sort |uniq))
len=${#ports[@]}

for ((i=0;i<=$len-1;i++))
do
    old=$(grep ${ports[i]} master_slave_map_old | md5sum | awk '{print $1}')
    new=$(grep ${ports[i]} master_slave_map_new | md5sum | awk '{print $1}')
    if [[ "${old}" != "${new}" ]];then
        echo -n "${ports[i]}主從實例切換前："
        grep ${ports[i]} master_slave_map_old
        echo -n "${ports[i]}主從實例切換后："
        grep ${ports[i]} master_slave_map_new
    fi
done

cat master_slave_map_new > master_slave_map_old
rm -rf master_slave_map_new

 

測試過程：

5.5.5.101:29001> info replication
# Replication
role:slave master_host:5.5.5.102 master_port:29001
master_link_status:up
master_last_io_seconds_ago:0
master_sync_in_progress:0
slave_repl_offset:360775
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:3c06fcc274b6fac6fe1d954f8b63687619e65cf5
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:360775
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:52428800
repl_backlog_first_byte_offset:1
repl_backlog_histlen:360775
lxd-vm1:29001> CLUSTER FAILOVER
OK
5.5.5.101:29001> info replication
# Replication
role:master connected_slaves:1 slave0:ip=5.5.5.102,port=29001,state=online,offset=361741,lag=1
master_replid:a35374725759383211f8f76d6b9376d181beda17
master_replid2:3c06fcc274b6fac6fe1d954f8b63687619e65cf5
master_repl_offset:361755
second_repl_offset:360888
repl_backlog_active:1
repl_backlog_size:52428800
repl_backlog_first_byte_offset:1
repl_backlog_histlen:361755
lxd-vm1:29001> 

測試結果

[redis@lxd-vm3 ~]$ sh a2.sh 5.5.5.101 29001
29001主從實例切換前：5.5.5.102:29001->5.5.5.101:29001
29001主從實例切換后：5.5.5.101:29001->5.5.5.102:29001
[redis@lxd-vm3 ~]$