diff --git a/cmd/tools/generate/counter.tmpl b/cmd/tools/generate/counter.tmpl
index e42c5aba9..583caec1a 100644
--- a/cmd/tools/generate/counter.tmpl
+++ b/cmd/tools/generate/counter.tmpl
@@ -1,8 +1,11 @@
-This document contains details about Harvest metrics and their relevant ONTAP ZAPI and REST API mappings.
+This document describes how Harvest metrics relate to their relevant ONTAP ZAPI and REST mappings, including:
-Details about which Harvest metrics each dashboard uses can be generated on demand by running `bin/harvest grafana metrics`. See
+- Details about which Harvest metrics each dashboard uses.
+These can be generated on demand by running `bin/harvest grafana metrics`. See
[#1577](https://github.com/NetApp/harvest/issues/1577#issue-1471478260) for details.
+- More information about ONTAP REST performance counters can be found [here](https://docs.netapp.com/us-en/ontap-pcmap-9121/index.html).
+
```
Creation Date : {{ .CounterMetaData.Date }}
ONTAP Version: {{ .CounterMetaData.OntapVersion }}
diff --git a/docs/ontap-metrics.md b/docs/ontap-metrics.md
index 86c61fd0b..3077e4ca3 100644
--- a/docs/ontap-metrics.md
+++ b/docs/ontap-metrics.md
@@ -1,8 +1,11 @@
-This document contains details about Harvest metrics and their relevant ONTAP ZAPI and REST API mappings.
+This document describes how Harvest metrics relate to their relevant ONTAP ZAPI and REST mappings, including:
-Details about which Harvest metrics each dashboard uses can be generated on demand by running `bin/harvest grafana metrics`. See
+- Details about which Harvest metrics each dashboard uses.
+These can be generated on demand by running `bin/harvest grafana metrics`. See
[#1577](https://github.com/NetApp/harvest/issues/1577#issue-1471478260) for details.
+- More information about ONTAP REST performance counters can be found [here](https://docs.netapp.com/us-en/ontap-pcmap-9121/index.html).
+
```
Creation Date : 2023-Apr-27
ONTAP Version: 9.12.1
@@ -844,6 +847,78 @@ Provides the sensor reading.
| ZAPI | `environment-sensors-get-iter` | `environment-sensors-info.threshold-sensor-value` | conf/zapi/cdot/9.8.0/sensor.yaml |
+### external_service_op_num_not_found_responses
+
+Number of 'Not Found' responses for calls to this operation.
+
+| API | Endpoint | Metric | Template |
+|--------|----------|--------|---------|
+| ZAPI | `perf-object-get-instances external_service_op` | `num_not_found_responses`
Unit: none
Type: delta
Base: | conf/zapiperf/cdot/9.8.0/external_service_operation.yaml |
+
+
+### external_service_op_num_request_failures
+
+A cumulative count of all request failures.
+
+| API | Endpoint | Metric | Template |
+|--------|----------|--------|---------|
+| ZAPI | `perf-object-get-instances external_service_op` | `num_request_failures`
Unit: none
Type: delta
Base: | conf/zapiperf/cdot/9.8.0/external_service_operation.yaml |
+
+
+### external_service_op_num_requests_sent
+
+Number of requests sent to this service.
+
+| API | Endpoint | Metric | Template |
+|--------|----------|--------|---------|
+| ZAPI | `perf-object-get-instances external_service_op` | `num_requests_sent`
Unit: none
Type: delta
Base: | conf/zapiperf/cdot/9.8.0/external_service_operation.yaml |
+
+
+### external_service_op_num_responses_received
+
+Number of responses received from the server (does not include timeouts).
+
+| API | Endpoint | Metric | Template |
+|--------|----------|--------|---------|
+| ZAPI | `perf-object-get-instances external_service_op` | `num_responses_received`
Unit: none
Type: delta
Base: | conf/zapiperf/cdot/9.8.0/external_service_operation.yaml |
+
+
+### external_service_op_num_successful_responses
+
+Number of successful responses to this operation.
+
+| API | Endpoint | Metric | Template |
+|--------|----------|--------|---------|
+| ZAPI | `perf-object-get-instances external_service_op` | `num_successful_responses`
Unit: none
Type: delta
Base: | conf/zapiperf/cdot/9.8.0/external_service_operation.yaml |
+
+
+### external_service_op_num_timeouts
+
+Number of times requests to the server for this operation timed out, meaning no response was recevied in a given time period.
+
+| API | Endpoint | Metric | Template |
+|--------|----------|--------|---------|
+| ZAPI | `perf-object-get-instances external_service_op` | `num_timeouts`
Unit: none
Type: delta
Base: | conf/zapiperf/cdot/9.8.0/external_service_operation.yaml |
+
+
+### external_service_op_request_latency
+
+Average latency of requests for operations of this type on this server.
+
+| API | Endpoint | Metric | Template |
+|--------|----------|--------|---------|
+| ZAPI | `perf-object-get-instances external_service_op` | `request_latency`
Unit: microsec
Type: average
Base: num_requests_sent | conf/zapiperf/cdot/9.8.0/external_service_operation.yaml |
+
+
+### external_service_op_request_latency_hist
+
+This histogram holds the latency values for requests of this operation to the specified server.
+
+| API | Endpoint | Metric | Template |
+|--------|----------|--------|---------|
+| ZAPI | `perf-object-get-instances external_service_op` | `request_latency_hist`
Unit: none
Type: delta
Base: | conf/zapiperf/cdot/9.8.0/external_service_operation.yaml |
+
+
### fabricpool_average_latency
Note This counter is deprecated and will be removed in a future release. Average latencies executed during various phases of command execution. The execution-start latency represents the average time taken to start executing a operation. The request-prepare latency represent the average time taken to prepare the commplete request that needs to be sent to the server. The send latency represents the average time taken to send requests to the server. The execution-start-to-send-complete represents the average time taken to send a operation out since its execution started. The execution-start-to-first-byte-received represent the average time taken to to receive the first byte of a response since the command's request execution started. These counters can be used to identify performance bottlenecks within the object store client module.
@@ -8317,6 +8392,7 @@ Histogram of latency for NFSv3 operations.
| API | Endpoint | Metric | Template |
|--------|----------|--------|---------|
+| REST | `api/cluster/counter/tables/svm_nfs_v3` | `latency_histogram`
Unit: none
Type: delta
Base: | conf/restperf/9.12.0/nfsv3.yaml |
| ZAPI | `perf-object-get-instances nfsv3` | `nfsv3_latency_hist`
Unit: none
Type: delta,no-zero-values
Base: | conf/zapiperf/cdot/9.8.0/nfsv3.yaml |
@@ -8766,6 +8842,7 @@ Histogram of latency for Read operations.
| API | Endpoint | Metric | Template |
|--------|----------|--------|---------|
+| REST | `api/cluster/counter/tables/svm_nfs_v3` | `read_latency_histogram`
Unit: none
Type: delta
Base: | conf/restperf/9.12.0/nfsv3.yaml |
| ZAPI | `perf-object-get-instances nfsv3` | `read_latency_hist`
Unit: none
Type: delta,no-zero-values
Base: | conf/zapiperf/cdot/9.8.0/nfsv3.yaml |
@@ -9285,6 +9362,7 @@ Histogram of latency for Write operations.
| API | Endpoint | Metric | Template |
|--------|----------|--------|---------|
+| REST | `api/cluster/counter/tables/svm_nfs_v3` | `write_latency_histogram`
Unit: none
Type: delta
Base: | conf/restperf/9.12.0/nfsv3.yaml |
| ZAPI | `perf-object-get-instances nfsv3` | `write_latency_hist`
Unit: none
Type: delta,no-zero-values
Base: | conf/zapiperf/cdot/9.8.0/nfsv3.yaml |