MongoDB monitoring

SkyWalking leverages mongodb-exporter for collecting metrics data from MongoDB. It leverages OpenTelemetry Collector to transfer the metrics to OpenTelemetry receiver and into the Meter System.

Data flow

  1. The mongodb-exporter collects metrics data from MongoDB. The exporter works side by side with the MongoDB node.
  2. OpenTelemetry Collector fetches metrics from mongodb-exporter via Prometheus Receiver and pushes metrics to SkyWalking OAP Server via OpenTelemetry gRPC exporter.
  3. The SkyWalking OAP Server parses the expression with MAL to filter/calculate/aggregate and store the results.

Setup

  1. Setup mongodb-exporter.
  2. Set up OpenTelemetry Collector. The example for OpenTelemetry Collector configuration, refer to here.
  3. Config SkyWalking OpenTelemetry receiver.

MongoDB Monitoring

MongoDB monitoring provides multidimensional metrics monitoring of MongoDB clusters as Layer: MONGODB Service in the OAP. In each cluster, the nodes are represented as Instance.

MongoDB Cluster Supported Metrics

Monitoring Panel Unit Metric Name Description Data Source
Uptime (day) day meter_mongodb_cluster_uptime Maximum uptime of nodes in the cluster mongodb-exporter
Data Size (GB) GB meter_mongodb_cluster_data_size Total data size of the cluster mongodb-exporter
Collection Count meter_mongodb_cluster_collection_count Number of collection of the cluster mongodb-exporter
Object Count meter_mongodb_cluster_object_count Number of object of the cluster mongodb-exporter
Document Avg QPS meter_mongodb_cluster_document_avg_qps Avg document operations rate of nodes mongodb-exporter
Operation Avg QPS meter_mongodb_cluster_operation_avg_qps Avg operations rate of nodes mongodb-exporter
Total Connections meter_mongodb_cluster_connections Cluster total connections of nodes mongodb-exporter
Cursor Avg meter_mongodb_cluster_cursor_avg Avg Opened cursor of nodes mongodb-exporter
Replication Lag (ms) ms meter_mongodb_cluster_repl_lag Repl set member avg replication lag, this metric works in repl mode mongodb-exporter
DB Avg Data Size Per Shard (GB) GB meter_mongodb_cluster_db_data_size Avg data size per shard (replSet) of every database mongodb-exporter
DB Avg Index Size Per Shard (GB) GB meter_mongodb_cluster_db_index_size Avg index size per shard (replSet) of every database mongodb-exporter
DB Avg Collection Count Per Shard meter_mongodb_cluster_db_collection_count Avg collection count per shard (replSet) of every database mongodb-exporter
DB Avg Index Count Per Shard meter_mongodb_cluster_db_index_count Avg index count per shard (replSet) of every database mongodb-exporter

MongoDB Node Supported Metrics

Monitoring Panel Unit Metric Name Description Data Source
Uptime (day) day meter_mongodb_node_uptime Uptime of the node mongodb-exporter
QPS meter_mongodb_node_qps Operations per second of the node mongodb-exporter
Latency µs meter_mongodb_node_latency Latency of operations mongodb-exporter
Memory Usage % meter_mongodb_node_memory_usage Memory usage percent of RAM mongodb-exporter
Version meter_mongodb_node_version MongoDB edition and version mongodb-exporter
ReplSet State meter_mongodb_node_rs_state Repl set state of the node, this metric works in repl mode mongodb-exporter
CPU Usage (%) % meter_mongodb_node_cpu_total_percentage Cpu usage percent of the node mongodb-exporter
Network (KB/s) KB/s meter_mongodb_node_network_bytes_in
meter_mongodb_node_network_bytes_out		 Inbound and outbound network bytes of node mongodb-exporter
Memory Free (GB) GB meter_mongodb_node_memory_free_kb
meter_mongodb_node_swap_memory_free_kb		 Free memory of RAM and swap mongodb-exporter
Disk (GB) GB meter_mongodb_node_fs_used_size
meter_mongodb_node_fs_total_size		 Used and total size of disk mongodb-exporter
Connections meter_mongodb_node_connections Connection nums of node mongodb-exporter
Active Client meter_mongodb_node_active_total_num
meter_mongodb_node_active_reader_num
meter_mongodb_node_active_writer_num		 Count of active reader and writer mongodb-exporter
Transactions meter_mongodb_node_transactions_active
meter_mongodb_node_transactions_inactive		 Count of transactions running on the node mongodb-exporter
Document QPS meter_mongodb_node_document_qps Document operations per second mongodb-exporter
Operation QPS meter_mongodb_node_operation_qps Operations per second mongodb-exporter
Repl Operation QPS meter_mongodb_node_repl_operation_qps Repl operations per second mongodb-exporter
Operation Latency (µs) µs meter_mongodb_node_operation_latency Latencies for different operation type mongodb-exporter
Cursor meter_mongodb_node_cursor Opened cursor of the node mongodb-exporter
Server Status Memory (MB) MB meter_mongodb_node_mem_virtual
meter_mongodb_node_mem_resident		 Virtual and resident memory of the node mongodb-exporter
Asserts meter_mongodb_node_asserts The rate of raised assertions mongodb-exporter
Repl Buffer Count meter_mongodb_node_repl_buffer_count The current number of operations in the oplog buffer mongodb-exporter
Repl Buffer Size (MB) MB meter_mongodb_node_repl_buffer_size
meter_mongodb_node_repl_buffer_size_max		 The maximum size of the oplog buffer mongodb-exporter
Queued Operation meter_mongodb_node_queued_operation The number of operations queued because of a lock mongodb-exporter
getLastError Write Num meter_mongodb_node_write_wait_num
meter_mongodb_node_write_wait_timeout_num		 The number of write concern operation mongodb-exporter
getLastError Write Time (ms) ms meter_mongodb_node_write_wait_time The wait time of write concern operation mongodb-exporter

Customizations

You can customize your own metrics/expression/dashboard panel. The metrics definition and expression rules are found in /config/otel-rules/mongodb/mongodb-cluster.yaml, /config/otel-rules/mongodb/mongodb-node.yaml. The MongoDB dashboard panel configurations are found in /config/ui-initialized-templates/mongodb.