diff --git a/agent/agent.go b/agent/agent.go
index 25487d0..c1d0633 100644
--- a/agent/agent.go
+++ b/agent/agent.go
@@ -22,6 +22,7 @@ import (
 	_ "flashcat.cloud/categraf/inputs/mem"
 	_ "flashcat.cloud/categraf/inputs/net"
 	_ "flashcat.cloud/categraf/inputs/netstat"
+	_ "flashcat.cloud/categraf/inputs/oracle"
 	_ "flashcat.cloud/categraf/inputs/processes"
 	_ "flashcat.cloud/categraf/inputs/redis"
 	_ "flashcat.cloud/categraf/inputs/system"
@@ -49,6 +50,7 @@ func (a *Agent) Stop() {
 	for name := range InputReaders {
 		InputReaders[name].QuitChan <- struct{}{}
 		close(InputReaders[name].Queue)
+		InputReaders[name].Instance.Drop()
 	}
 
 	log.Println("I! agent stopped")
diff --git a/conf/input.oracle/metric.toml b/conf/input.oracle/metric.toml
new file mode 100644
index 0000000..5298d38
--- /dev/null
+++ b/conf/input.oracle/metric.toml
@@ -0,0 +1,85 @@
+[[metrics]]
+mesurement = "sessions"
+label_fields = [ "status", "type" ]
+metric_fields = { value = "float64" }
+timeout = "3s"
+request = '''
+SELECT status, type, COUNT(*) as value FROM v$session GROUP BY status, type
+'''
+
+[[metrics]]
+mesurement = "resource"
+label_fields = [ "resource_name" ]
+metric_fields = { current_utilization= "float64", limit_value="float64" }
+timeout = "3s"
+request = '''
+SELECT resource_name,current_utilization,CASE WHEN TRIM(limit_value) LIKE 'UNLIMITED' THEN '-1' ELSE TRIM(limit_value) END as limit_value FROM v$resource_limit
+'''
+
+[[metrics]]
+mesurement = "asm_diskgroup"
+label_fields = [ "name" ]
+metric_fields = { total = "float64", free = "float64" }
+timeout = "3s"
+request = '''
+SELECT name,total_mb*1024*1024 as total,free_mb*1024*1024 as free FROM v$asm_diskgroup_stat where exists (select 1 from v$datafile where name like '+%')
+'''
+IgnoreZeroResult = true
+
+[[metrics]]
+mesurement = "activity"
+metric_fields = { value = "float64" }
+field_to_append = "name"
+timeout = "3s"
+request = '''
+SELECT name, value FROM v$sysstat WHERE name IN ('parse count (total)', 'execute count', 'user commits', 'user rollbacks')
+'''
+
+[[metrics]]
+mesurement = "process"
+metric_fields = { count = "float64" }
+timeout = "3s"
+request = '''
+SELECT COUNT(*) as count FROM v$process
+'''
+
+[[metrics]]
+mesurement = "wait_time"
+metric_fields = { value = "float64" }
+label_fields = ["wait_class"]
+timeout = "3s"
+request = '''
+SELECT
+  n.wait_class as WAIT_CLASS,
+  round(m.time_waited/m.INTSIZE_CSEC,3) as VALUE
+FROM
+  v$waitclassmetric  m, v$system_wait_class n
+WHERE
+  m.wait_class_id=n.wait_class_id AND n.wait_class != 'Idle'
+'''
+
+[[metrics]]
+mesurement = "tablespace"
+label_fields = [ "tablespace", "type" ]
+metric_fields = { bytes = "float64", max_bytes = "float64", free = "float64" }
+timeout = "3s"
+request = '''
+SELECT
+    dt.tablespace_name as tablespace,
+    dt.contents as type,
+    dt.block_size * dtum.used_space as bytes,
+    dt.block_size * dtum.tablespace_size as max_bytes,
+    dt.block_size * (dtum.tablespace_size - dtum.used_space) as free
+FROM  dba_tablespace_usage_metrics dtum, dba_tablespaces dt
+WHERE dtum.tablespace_name = dt.tablespace_name
+ORDER by tablespace
+'''
+
+[[metrics]]
+mesurement = "sysmetric"
+metric_fields = { value = "float64" }
+field_to_append = "metric_name"
+timeout = "3s"
+request = '''
+select METRIC_NAME,VALUE from v$sysmetric where group_id=2
+'''
diff --git a/conf/input.oracle/oracle.toml b/conf/input.oracle/oracle.toml
new file mode 100644
index 0000000..11487b5
--- /dev/null
+++ b/conf/input.oracle/oracle.toml
@@ -0,0 +1,19 @@
+[[instances]]
+address = "10.1.2.3:1521/orcl"
+username = "monitor"
+password = "123456"
+is_sys_dba = false
+is_sys_oper = false
+disable_connection_pool = false
+max_open_connections = 5
+# labels = {region="cloud"}
+
+# [[instances]]
+# address = "192.168.10.10:1521/orcl"
+# username = "monitor"
+# password = "123456"
+# is_sys_dba = false
+# is_sys_oper = false
+# disable_connection_pool = false
+# max_open_connections = 5
+# # labels = {region="local"}
diff --git a/go.mod b/go.mod
index 7ca4c49..dfe1a53 100644
--- a/go.mod
+++ b/go.mod
@@ -4,9 +4,11 @@ go 1.17
 
 require (
 	github.com/gobwas/glob v0.2.3
+	github.com/godror/godror v0.33.0
 	github.com/golang/protobuf v1.5.2
 	github.com/golang/snappy v0.0.4
 	github.com/influxdata/line-protocol/v2 v2.2.1
+	github.com/jmoiron/sqlx v1.3.5
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/koding/multiconfig v0.0.0-20171124222453-69c27309b2d7
 	github.com/prometheus/client_golang v1.12.1
@@ -20,7 +22,10 @@ require (
 	github.com/BurntSushi/toml v1.1.0 // indirect
 	github.com/fatih/camelcase v1.0.0 // indirect
 	github.com/fatih/structs v1.1.0 // indirect
+	github.com/go-logfmt/logfmt v0.5.1 // indirect
+	github.com/go-logr/logr v1.2.3 // indirect
 	github.com/go-ole/go-ole v1.2.6 // indirect
+	github.com/godror/knownpb v0.1.0 // indirect
 	github.com/gogo/protobuf v1.1.1 // indirect
 	github.com/grpc-ecosystem/grpc-gateway v1.16.0 // indirect
 	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect
@@ -34,6 +39,6 @@ require (
 	golang.org/x/text v0.3.7 // indirect
 	google.golang.org/genproto v0.0.0-20200825200019-8632dd797987 // indirect
 	google.golang.org/grpc v1.33.1 // indirect
-	google.golang.org/protobuf v1.26.0 // indirect
+	google.golang.org/protobuf v1.27.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 3102bb5..010e69c 100644
--- a/go.sum
+++ b/go.sum
@@ -81,15 +81,25 @@ github.com/go-kit/log v0.1.0/go.mod h1:zbhenjAZHb184qTLMA9ZjW7ThYL0H2mk7Q6pNt4vb
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
 github.com/go-logfmt/logfmt v0.5.0/go.mod h1:wCYkCAKZfumFQihp8CzCvQ3paCTfi41vtzG1KdI/P7A=
+github.com/go-logfmt/logfmt v0.5.1 h1:otpy5pqBCBZ1ng9RQ0dPu4PN7ba75Y/aA+UpowDyNVA=
+github.com/go-logfmt/logfmt v0.5.1/go.mod h1:WYhtIu8zTZfxdn5+rREduYbwxfcBr/Vr6KEVveWlfTs=
+github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
+github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-ole/go-ole v1.2.6 h1:/Fpf6oFPoeFik9ty7siob0G6Ke8QvQEuVcuChpwXzpY=
 github.com/go-ole/go-ole v1.2.6/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0=
 github.com/go-playground/assert/v2 v2.0.1/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
 github.com/go-playground/locales v0.13.0/go.mod h1:taPMhCMXrRLJO55olJkUXHZBHCxTMfnGwq/HNwmWNS8=
 github.com/go-playground/universal-translator v0.17.0/go.mod h1:UkSxE5sNxxRwHyU+Scu5vgOQjsIJAF8j9muTVoKLVtA=
 github.com/go-playground/validator/v10 v10.4.1/go.mod h1:nlOn6nFhuKACm19sB/8EGNn9GlaMV7XkbRSipzJ0Ii4=
+github.com/go-sql-driver/mysql v1.6.0 h1:BCTh4TKNUYmOmMUcQ3IipzF5prigylS7XXjEkfCHuOE=
+github.com/go-sql-driver/mysql v1.6.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/gobwas/glob v0.2.3 h1:A4xDbljILXROh+kObIiy5kIaPYD8e96x1tgBhUI5J+Y=
 github.com/gobwas/glob v0.2.3/go.mod h1:d3Ez4x06l9bZtSvzIay5+Yzi0fmZzPgnTbPcKjJAkT8=
+github.com/godror/godror v0.33.0 h1:ZK1W7GohHVDPoLp/37U9QCSHARnYB4vVxNJya+CyWQ4=
+github.com/godror/godror v0.33.0/go.mod h1:qHYnDISFm/h0vM+HDwg0LpyoLvxRKFRSwvhYF7ufjZ8=
+github.com/godror/knownpb v0.1.0 h1:dJPK8s/I3PQzGGaGcUStL2zIaaICNzKKAK8BzP1uLio=
+github.com/godror/knownpb v0.1.0/go.mod h1:4nRFbQo1dDuwKnblRXDxrfCFYeT4hjg3GjMqef58eRE=
 github.com/gogo/protobuf v1.1.1 h1:72R+M5VuhED/KujmZVcIquuo8mBgX4oVda//DQb3PXo=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
@@ -163,6 +173,8 @@ github.com/influxdata/line-protocol/v2 v2.0.0-20210312151457-c52fdecb625a/go.mod
 github.com/influxdata/line-protocol/v2 v2.1.0/go.mod h1:QKw43hdUBg3GTk2iC3iyCxksNj7PX9aUSeYOYE/ceHY=
 github.com/influxdata/line-protocol/v2 v2.2.1 h1:EAPkqJ9Km4uAxtMRgUubJyqAr6zgWM0dznKMLRauQRE=
 github.com/influxdata/line-protocol/v2 v2.2.1/go.mod h1:DmB3Cnh+3oxmG6LOBIxce4oaL4CPj3OmMPgvauXh+tM=
+github.com/jmoiron/sqlx v1.3.5 h1:vFFPA71p1o5gAeqtEAwLU4dnX2napprKtHr7PYIcN3g=
+github.com/jmoiron/sqlx v1.3.5/go.mod h1:nRVWtLre0KfCLJvgxzCsLVMogSvQ1zNJtpYr2Ccp0mQ=
 github.com/jpillora/backoff v1.0.0/go.mod h1:J/6gKK9jxlEcS3zixgDgUAsiuZ7yrSoa/FX5e0EB2j4=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
@@ -189,9 +201,13 @@ github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
+github.com/lib/pq v1.2.0 h1:LXpIM/LZ5xGFhOpXAQUIMM1HdyqzVYM13zNdjCEEcA0=
+github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 h1:6E+4a0GO5zZEnZ81pIr0yLvtUWk2if982qA3F3QD6H4=
 github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0/go.mod h1:zJYVVT2jmtg6P3p1VtQj7WsuWi/y4VnjVBn7F8KPB3I=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
+github.com/mattn/go-sqlite3 v1.14.6 h1:dNPt6NO46WmLVt2DLNpwczCmdV5boIZ6g/tlDrlRUbg=
+github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -202,6 +218,9 @@ github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRW
 github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
+github.com/oklog/ulid/v2 v2.0.2 h1:r4fFzBm+bv0wNKNh5eXTwU7i85y5x+uwkxCUTNVQqLc=
+github.com/oklog/ulid/v2 v2.0.2/go.mod h1:mtBL0Qe/0HAx6/a4Z30qxVIAL1eQDweXq5lxOEiwQ68=
+github.com/pborman/getopt v0.0.0-20170112200414-7148bc3a4c30/go.mod h1:85jBQOZwpVEaDAr341tbn15RS4fCAsIst0qp7i8ex1o=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
@@ -347,6 +366,7 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201207232520-09787c993a3a h1:DcqTD9SDLc+1P/r1EmRBwnVsrOwW+kk2vWf9n+1sGhs=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -524,8 +544,9 @@ google.golang.org/protobuf v1.23.1-0.20200526195155-81db48ad09cc/go.mod h1:EGpAD
 google.golang.org/protobuf v1.24.0/go.mod h1:r/3tXBNzIEhYS9I1OUVjXDlt8tc493IdKGjtUeSXeh4=
 google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlbajtzgsN7c=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
-google.golang.org/protobuf v1.26.0 h1:bxAC2xTBsZGibn2RTntX0oH50xLsqy1OxA9tTL3p/lk=
 google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.27.1 h1:SnqbnDw1V7RiZcXPx5MEeqPv2s79L9i7BJUlG/+RurQ=
+google.golang.org/protobuf v1.27.1/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
diff --git a/inputs/cpu/cpu.go b/inputs/cpu/cpu.go
index 4ed3e29..47f773f 100644
--- a/inputs/cpu/cpu.go
+++ b/inputs/cpu/cpu.go
@@ -44,6 +44,9 @@ func (c *CPUStats) Init() error {
 	return nil
 }
 
+func (c *CPUStats) Drop() {
+}
+
 func (c *CPUStats) Gather() []*types.Sample {
 	var samples []*types.Sample
 
diff --git a/inputs/disk/disk.go b/inputs/disk/disk.go
index 0be533e..85c5ff0 100644
--- a/inputs/disk/disk.go
+++ b/inputs/disk/disk.go
@@ -38,11 +38,13 @@ func (s *DiskStats) GetInterval() config.Duration {
 	return s.Interval
 }
 
-// overwrite func
 func (s *DiskStats) Init() error {
 	return nil
 }
 
+func (s *DiskStats) Drop() {
+}
+
 func (s *DiskStats) Gather() []*types.Sample {
 	var samples []*types.Sample
 
diff --git a/inputs/diskio/diskio.go b/inputs/diskio/diskio.go
index c025aeb..998920d 100644
--- a/inputs/diskio/diskio.go
+++ b/inputs/diskio/diskio.go
@@ -39,7 +39,8 @@ func (d *DiskIO) GetInterval() config.Duration {
 	return d.Interval
 }
 
-// overwrite func
+func (d *DiskIO) Drop() {}
+
 func (d *DiskIO) Init() error {
 	for _, device := range d.Devices {
 		if filter.HasMeta(device) {
diff --git a/inputs/exec/exec.go b/inputs/exec/exec.go
index 02b5b12..e9bfa7e 100644
--- a/inputs/exec/exec.go
+++ b/inputs/exec/exec.go
@@ -47,6 +47,8 @@ func (e *Exec) GetInputName() string {
 	return ""
 }
 
+func (e *Exec) Drop() {}
+
 func (e *Exec) GetInterval() config.Duration {
 	return e.Interval
 }
diff --git a/inputs/inputs.go b/inputs/inputs.go
index b6a19e4..d165de1 100644
--- a/inputs/inputs.go
+++ b/inputs/inputs.go
@@ -8,6 +8,7 @@ import (
 
 type Input interface {
 	Init() error
+	Drop()
 	GetInputName() string
 	GetInterval() config.Duration
 	Gather() []*types.Sample
diff --git a/inputs/kernel/kernel.go b/inputs/kernel/kernel.go
index 624c038..e36f5b8 100644
--- a/inputs/kernel/kernel.go
+++ b/inputs/kernel/kernel.go
@@ -56,6 +56,8 @@ func (s *KernelStats) Init() error {
 	return nil
 }
 
+func (s *KernelStats) Drop() {}
+
 func (s *KernelStats) Gather() (samples []*types.Sample) {
 	data, err := s.getProcStat()
 	if err != nil {
diff --git a/inputs/linux_sysctl_fs/linux_sysctl_fs_linux.go b/inputs/linux_sysctl_fs/linux_sysctl_fs_linux.go
index 5381bad..85cb51f 100644
--- a/inputs/linux_sysctl_fs/linux_sysctl_fs_linux.go
+++ b/inputs/linux_sysctl_fs/linux_sysctl_fs_linux.go
@@ -46,6 +46,8 @@ func (s *SysctlFS) Init() error {
 	return nil
 }
 
+func (s *SysctlFS) Drop() {}
+
 func (s *SysctlFS) Gather() []*types.Sample {
 	fields := map[string]interface{}{}
 
diff --git a/inputs/mem/mem.go b/inputs/mem/mem.go
index 926e62c..b205b68 100644
--- a/inputs/mem/mem.go
+++ b/inputs/mem/mem.go
@@ -38,7 +38,8 @@ func (s *MemStats) GetInterval() config.Duration {
 	return s.Interval
 }
 
-// overwrite func
+func (s *MemStats) Drop() {}
+
 func (s *MemStats) Init() error {
 	s.platform = runtime.GOOS
 	return nil
diff --git a/inputs/net/net.go b/inputs/net/net.go
index d51be78..7bd1ad9 100644
--- a/inputs/net/net.go
+++ b/inputs/net/net.go
@@ -42,7 +42,8 @@ func (s *NetIOStats) GetInterval() config.Duration {
 	return s.Interval
 }
 
-// overwrite func
+func (s *NetIOStats) Drop() {}
+
 func (s *NetIOStats) Init() error {
 	var err error
 
diff --git a/inputs/netstat/netstat.go b/inputs/netstat/netstat.go
index dbb97e1..f5aa0ca 100644
--- a/inputs/netstat/netstat.go
+++ b/inputs/netstat/netstat.go
@@ -36,6 +36,8 @@ func (s *NetStats) GetInterval() config.Duration {
 	return s.Interval
 }
 
+func (s *NetStats) Drop() {}
+
 func (s *NetStats) Init() error {
 	return nil
 }
diff --git a/inputs/oracle/oracle.go b/inputs/oracle/oracle.go
new file mode 100644
index 0000000..5c655c3
--- /dev/null
+++ b/inputs/oracle/oracle.go
@@ -0,0 +1,144 @@
+package oracle
+
+import (
+	"fmt"
+	"log"
+	"sync"
+
+	"flashcat.cloud/categraf/config"
+	"flashcat.cloud/categraf/inputs"
+	"flashcat.cloud/categraf/types"
+	"github.com/godror/godror"
+	"github.com/godror/godror/dsn"
+	"github.com/jmoiron/sqlx"
+	"github.com/toolkits/pkg/container/list"
+)
+
+const inputName = "oracle"
+
+type OrclInstance struct {
+	Address               string `toml:"address"`
+	Username              string `toml:"username"`
+	Password              string `toml:"password"`
+	IsSysDBA              bool   `toml:"is_sys_dba"`
+	IsSysOper             bool   `toml:"is_sys_oper"`
+	DisableConnectionPool bool   `toml:"disable_connection_pool"`
+	MaxOpenConnections    int    `toml:"max_open_connections"`
+}
+
+type MetricConfig struct {
+	Mesurement       string            `toml:"mesurement"`
+	LabelFields      []string          `toml:"label_fields"`
+	MetricFields     map[string]string `toml:"metric_fields"` // column_name -> value type(float64, bool, int64)
+	FieldToAppend    string            `toml:"field_to_append"`
+	Timeout          config.Duration   `toml:"timeout"`
+	Request          string            `toml:"request"`
+	IgnoreZeroResult bool              `toml:"ignore_zero_result"`
+}
+
+type Oracle struct {
+	PrintConfigs bool            `toml:"print_configs"`
+	Interval     config.Duration `toml:"interval"`
+	Instances    []OrclInstance  `toml:"instances"`
+	Metrics      []MetricConfig  `toml:"metrics"`
+
+	dbconnpool map[string]*sqlx.DB // key: instance
+}
+
+func init() {
+	inputs.Add(inputName, func() inputs.Input {
+		return &Oracle{}
+	})
+}
+
+func (o *Oracle) GetInputName() string {
+	return inputName
+}
+
+func (o *Oracle) GetInterval() config.Duration {
+	return o.Interval
+}
+
+func (o *Oracle) Init() error {
+	if len(o.Instances) == 0 {
+		return fmt.Errorf("oracle instances empty")
+	}
+
+	o.dbconnpool = make(map[string]*sqlx.DB)
+	for i := 0; i < len(o.Instances); i++ {
+		dbConf := o.Instances[i]
+		connString := getConnectionString(dbConf)
+		db, err := sqlx.Open("godror", connString)
+		if err != nil {
+			return fmt.Errorf("failed to open oracle connection: %v", err)
+		}
+		db.SetMaxOpenConns(dbConf.MaxOpenConnections)
+		o.dbconnpool[dbConf.Address] = db
+	}
+
+	return nil
+}
+
+func (o *Oracle) Drop() {
+	for address := range o.dbconnpool {
+		if config.Config.DebugMode {
+			log.Println("D! dropping oracle connection:", address)
+		}
+		if err := o.dbconnpool[address].Close(); err != nil {
+			log.Println("E! failed to close oracle connection:", address, "error:", err)
+		}
+	}
+}
+
+func (o *Oracle) Gather() (samples []*types.Sample) {
+	slist := list.NewSafeList()
+
+	var wg sync.WaitGroup
+	for i := range o.Instances {
+		wg.Add(1)
+		go o.collectOnce(&wg, o.Instances[i], slist)
+	}
+	wg.Wait()
+
+	interfaceList := slist.PopBackAll()
+	for i := 0; i < len(interfaceList); i++ {
+		samples = append(samples, interfaceList[i].(*types.Sample))
+	}
+
+	return
+}
+
+func (o *Oracle) collectOnce(wg *sync.WaitGroup, ins OrclInstance, slist *list.SafeList) {
+	log.Println("->", ins.Address)
+	log.Printf("%#v\n", ins)
+	log.Println("-> metrics count:", len(o.Metrics))
+
+	log.Println(o.Metrics[0].Mesurement)
+	log.Println(o.Metrics[0].Request)
+	log.Println(o.Metrics[0].FieldToAppend)
+	log.Println(o.Metrics[0].IgnoreZeroResult)
+	log.Println(o.Metrics[0].LabelFields)
+	log.Println(o.Metrics[0].MetricFields)
+
+	defer wg.Done()
+}
+
+func getConnectionString(args OrclInstance) string {
+	return godror.ConnectionParams{
+		StandaloneConnection: args.DisableConnectionPool,
+		CommonParams: dsn.CommonParams{
+			Username:      args.Username,
+			Password:      dsn.NewPassword(args.Password),
+			ConnectString: args.Address,
+		},
+		PoolParams: dsn.PoolParams{
+			MinSessions:      0,
+			MaxSessions:      args.MaxOpenConnections,
+			SessionIncrement: 1,
+		},
+		ConnParams: dsn.ConnParams{
+			IsSysDBA:  args.IsSysDBA,
+			IsSysOper: args.IsSysOper,
+		},
+	}.StringWithPassword()
+}
diff --git a/inputs/processes/processes_notwindows.go b/inputs/processes/processes_notwindows.go
index ea2526e..16738c7 100644
--- a/inputs/processes/processes_notwindows.go
+++ b/inputs/processes/processes_notwindows.go
@@ -43,6 +43,8 @@ func (p *Processes) GetInterval() config.Duration {
 	return p.Interval
 }
 
+func (p *Processes) Drop() {}
+
 func (p *Processes) Init() error {
 	return nil
 }
diff --git a/inputs/system/system.go b/inputs/system/system.go
index a4e9a57..6d0922d 100644
--- a/inputs/system/system.go
+++ b/inputs/system/system.go
@@ -35,11 +35,12 @@ func (s *SystemStats) GetInterval() config.Duration {
 	return s.Interval
 }
 
-// overwrite func
 func (s *SystemStats) Init() error {
 	return nil
 }
 
+func (s *SystemStats) Drop() {}
+
 func (s *SystemStats) Gather() []*types.Sample {
 	var samples []*types.Sample