When my ZABBIX proxy VPS reached 4000, I found that the data sending process of ZABBIX proxy would be 100% all the time, and the data receiving process of zabbix-server would be delayed.

This is my zabbix-proxy configuration file：

AllowRoot=0
CacheSize=8G
ConfigFrequency=60
DataSenderFrequency=60
DBHost=localhost
DBName=zabbix_proxy
DBPassword=zabbix123
DBPort=10240
DBSocket=/data/mysql/log/mysqld.sock
DBUser=root
DebugLevel=3
EnableRemoteCommands=1
Fping6Location=/usr/sbin/fping6
FpingLocation=/usr/sbin/fping
HeartbeatFrequency=60
HistoryCacheSize=2G
HistoryIndexCacheSize=2G
Hostname=zabbix-proxy001
HousekeepingFrequency=1
JavaGateway=0.0.0.0
JavaGatewayPort=10052
ListenIP=0.0.0.0
ListenPort=10051
LogFile=/data/zabbix/zabbix_proxy.log
LogFileSize=1024
LogRemoteCommands=1
LogSlowQueries=0
LogType=file
PidFile=/var/run/zabbix/zabbix_proxy.pid
ProxyLocalBuffer=0
ProxyMode=0
ProxyOfflineBuffer=2
ServerPort=10051
Server=10.114.100.10
SocketDir=/var/run/zabbix
StartDBSyncers=32
StartDiscoverers=16
StartHTTPPollers=5
StartIPMIPollers=10
StartJavaPollers=16
StartPingers=32
StartPollers=32
StartPollersUnreachable=32
StartTrappers=24
Timeout=30
TLSAccept=unencrypted
TLSConnect=unencrypted
TmpDir=/tmp
TrapperTimeout=300
UnavailableDelay=60
UnreachableDelay=60
UnreachablePeriod=45
User=zabbix