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Storage Metrics

Introduction

Currently, Nebula Graph supports obtaining the basic performance metrics for the storage service via HTTP.

Each performance metric consists of three parts, namely <counter_name>.<statistic_type>.<time_range>, details are introduced as the follows.

Counter Names

Each counter name is composed of the interface name and the counter name. Currently, the supported interfaces are:

storage_vertex_props // obtain properties of a vertex
storage_edge_props // obtain properties of an edge
storage_add_vertex // insert a vertex
storage_add_edge // insert an edge
storage_del_vertex // delete a vertex
storage_update_vertex // update properties of a vertex
storage_update_edge // update properties of an edge
storage_get_kv // read kv pair
storage_put_kv // put kv pair
storage_get_bound // internal use only

Each interface has three metrics, namely latency (in the units of us), QPS and QPS with errors. The suffixes are as follows:

_latency
_qps
_error_qps

The complete metric concatenates the interface name with the corresponding metric, such as storage_add_vertex_latency, storage_add_vertex_qps and storage_add_vertex_error_qps, representing the latency, QPS, and the QPS with errors of inserting a vertex, respectively.

Statistics Type

Currently supported types are SUM, COUNT, AVG, RATE, and P quantiles (P99, P999, ..., P999999). Among which:

  • Metrics have suffixes _qps and _error_qps support SUM, COUNT, AVG, RATE but don't support P quantiles.
  • Metrics have suffixes _latency support SUM, COUNT, AVG, RATE, and P quantiles.

Time Range

Currently, the supported time ranges are 60s, 600s, and 3600s, which correspond to the last minute, the last ten minutes, and the last hour till now.

Obtain the Corresponding Metrics via HTTP Interface

According to the above introduction, you can make a complete metrics name, here are some examples:

storage_add_vertex_latency.avg.60   // the average latency of inserting a vertex in the last minute
storage_get_bound_qps.rate.600  // obtain neighbor's QPS in the last ten minutes
storage_update_edge_error_qps.count.3600  // errors occurred in updating an edge in the last hour

Assume that a Nebula Graph storage service is started locally, and the ws_http_port port number is set to 12000 when starting. It is sent through the GET interface of HTTP. The method name is get_stats, and the parameter is stats plus the corresponding metrics name. Here's an example of getting metrics via the HTTP interface:

# obtain a metrics
curl -G "http://127.0.0.1:12000/get_stats?stats=storage_vertex_props_qps.rate.60"
# storage_vertex_props_qps.rate.60=2674

# obtain multiple metrics at the same time
curl -G "http://127.0.0.1:12000/get_stats?stats=storage_vertex_props_qps.rate.60,storage_vertex_props_latency.avg.60"
# storage_vertex_props_qps.rate.60=2638
# storage_vertex_props_latency.avg.60=812

# obtain multiple metrics at the same time and return in json format
curl -G "http://127.0.0.1:12000/get_stats?stats=storage_vertex_props_qps.rate.60,storage_vertex_props_latency.avg.60&returnjson"
# [{"value":2723,"name":"storage_vertex_props_qps.rate.60"},{"value":804,"name":"storage_vertex_props_latency.avg.60"}]

# obtain all the metrics
curl -G "http://127.0.0.1:12000/get_stats?stats"
# or
curl -G "http://127.0.0.1:12000/get_stats"