Azure Managed Instance for Apache Cassandra Monitoring

From both a data and infrastructure perspective, this Prometheus Extension 2.0 allows you to monitors and analyze the activity of your Apache Cassandra clusters. It visualize your cluster's health and shows metrics like CPU, connectivity, request latency, suspension, and garbage collection time. Additionally, with Davis, it automatically detects performance problems and provides precise root cause analysis.

Prerequisites

Azure Managed Instance for Apache Cassandra created and running.
An Ubuntu virtual machine deployed inside the Azure Virtual Network where the managed instance is present.
Prometheus server set up to scrape Cassandra nodes and with relabel config in place.
Environment ActiveGate version 1.231+ with access to the Prometheus server

Setup

Create an Ubuntu virtual machine in the same virtual network as your Azure Managed Instance for Apache Cassandra.
Ensure Docker is installed on your virtual machine.
Create a file named prometheus.yml on your virtual machine with the contents below.
Add every Cassandra Node IP address and port 9443 in the static_configs section. The IP addresses can be gathered from the Data Center section of the Azure Portal for your Cassandra Cluster.
```
static_configs:
    - targets: ["<Node_IP_1>:9443", "<Node_IP_2>:9443", "<Node_IP_N>:9443"]
```

global:
  scrape_interval: 15s
  scrape_timeout: 10s
  evaluation_interval: 15s

alerting:
  alertmanagers:
  - static_configs:
    - targets: []
    scheme: http
    timeout: 10s

scrape_configs:
  - job_name: prometheus
    scrape_interval: 15s
    scrape_timeout: 15s
    metrics_path: /metrics
    scheme: http
    static_configs:
    - targets:
      - localhost:9090

  - job_name: "mcac"
    scrape_interval: 15s
    scrape_timeout:  15s
    static_configs:
      - targets: ["<Node_IP_1>:9443", "<Node_IP_2>:9443", "<Node_IP_N>:9443"]
    honor_labels: true
    honor_timestamps: false
    scheme: https
    tls_config:
            insecure_skip_verify: true
    metric_relabel_configs:
    #drop metrics we can calculate from prometheus directly
    - source_labels: [__name__]
      regex: .*rate_(mean|1m|5m|15m)
      action: drop
    #save the original name for all metrics
    - source_labels: [__name__]
      regex: (collectd_mcac_.+)
      target_label: prom_name
      replacement: ${1}
    - source_labels: ["prom_name"]
      regex: .+_bucket_(\d+)
      target_label: le
      replacement: ${1}
    - source_labels: ["prom_name"]
      regex: .+_bucket_inf
      target_label: le
      replacement: +Inf
    - source_labels: ["prom_name"]
      regex: .*_histogram_p(\d+)
      target_label: quantile
      replacement: .${1}
    - source_labels: ["prom_name"]
      regex: .*_histogram_min
      target_label: quantile
      replacement: "0"
    - source_labels: ["prom_name"]
      regex: .*_histogram_max
      target_label: quantile
      replacement: "1"
    #Table Metrics *ALL* we can drop
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.table\.(\w+)
      action: drop
    #Table Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.table\.(\w+)\.(\w+)\.(\w+)
      target_label: table
      replacement: ${3}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.table\.(\w+)\.(\w+)\.(\w+)
      target_label: keyspace
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.table\.(\w+)\.(\w+)\.(\w+)
      target_label: __name__
      replacement: mcac_table_${1}
    #Keyspace Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.keyspace\.(\w+)\.(\w+)
      target_label: keyspace
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.keyspace\.(\w+)\.(\w+)
      target_label: __name__
      replacement: mcac_keyspace_${1}
    #ThreadPool Metrics (one type is repair.task so we just ignore the second part)
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.thread_pools\.(\w+)\.(\w+)\.(\w+).*
      target_label: pool_type
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.thread_pools\.(\w+)\.(\w+)\.(\w+).*
      target_label: pool_name
      replacement: ${3}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.thread_pools\.(\w+)\.(\w+)\.(\w+).*
      target_label: __name__
      replacement: mcac_thread_pools_${1}
    #ClientRequest Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.client_request\.(\w+)\.(\w+)$
      target_label: request_type
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.client_request\.(\w+)\.(\w+)$
      target_label: __name__
      replacement: mcac_client_request_${1}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.client_request\.(\w+)\.(\w+)\.(\w+)$
      target_label: cl
      replacement: ${3}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.client_request\.(\w+)\.(\w+)\.(\w+)$
      target_label: request_type
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.client_request\.(\w+)\.(\w+)\.(\w+)$
      target_label: __name__
      replacement: mcac_client_request_${1}_cl
    #Cache Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.cache\.(\w+)\.(\w+)
      target_label: cache_name
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.cache\.(\w+)\.(\w+)
      target_label: __name__
      replacement: mcac_cache_${1}
    #CQL Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.cql\.(\w+)
      target_label: __name__
      replacement: mcac_cql_${1}
    #Dropped Message Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.dropped_message\.(\w+)\.(\w+)
      target_label: message_type
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.dropped_message\.(\w+)\.(\w+)
      target_label: __name__
      replacement: mcac_dropped_message_${1}
    #Streaming Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.streaming\.(\w+)\.(.+)$
      target_label: peer_ip
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.streaming\.(\w+)\.(.+)$
      target_label: __name__
      replacement: mcac_streaming_${1}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.streaming\.(\w+)$
      target_label: __name__
      replacement: mcac_streaming_${1}
    #CommitLog Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.commit_log\.(\w+)
      target_label: __name__
      replacement: mcac_commit_log_${1}
    #Compaction Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.compaction\.(\w+)
      target_label: __name__
      replacement: mcac_compaction_${1}
    #Storage Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.storage\.(\w+)
      target_label: __name__
      replacement: mcac_storage_${1}
    #Batch Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.batch\.(\w+)
      target_label: __name__
      replacement: mcac_batch_${1}
    #Client Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.client\.(\w+)
      target_label: __name__
      replacement: mcac_client_${1}
    #BufferPool Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.buffer_pool\.(\w+)
      target_label: __name__
      replacement: mcac_buffer_pool_${1}
    #Index Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.index\.(\w+)
      target_label: __name__
      replacement: mcac_sstable_index_${1}
    #HintService Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.hinted_hand_off_manager\.([^\-]+)-(\w+)
      target_label: peer_ip
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.hinted_hand_off_manager\.([^\-]+)-(\w+)
      target_label: __name__
      replacement: mcac_hints_${1}
    #HintService Metrics
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.hints_service\.hints_delays\-(\w+)
      target_label: peer_ip
      replacement: ${1}
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.hints_service\.hints_delays\-(\w+)
      target_label: __name__
      replacement: mcac_hints_hints_delays
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.hints_service\.([^\-]+)
      target_label: __name__
      replacement: mcac_hints_${1}
    # Misc
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.memtable_pool\.(\w+)
      target_label: __name__
      replacement: mcac_memtable_pool_${1}
    - source_labels: ["mcac"]
      regex: com\.datastax\.bdp\.type\.performance_objects\.name\.cql_slow_log\.metrics\.queries_latency
      target_label: __name__
      replacement: mcac_cql_slow_log_query_latency
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.read_coordination\.(.*)
      target_label: read_type
      replacement: $1
    - source_labels: ["mcac"]
      regex: org\.apache\.cassandra\.metrics\.read_coordination\.(.*)
      target_label: __name__
      replacement: mcac_read_coordination_requests
    #GC Metrics
    - source_labels: ["mcac"]
      regex: jvm\.gc\.(\w+)\.(\w+)
      target_label: collector_type
      replacement: ${1}
    - source_labels: ["mcac"]
      regex: jvm\.gc\.(\w+)\.(\w+)
      target_label: __name__
      replacement: mcac_jvm_gc_${2}
    #JVM Metrics
    - source_labels: ["mcac"]
      regex: jvm\.memory\.(\w+)\.(\w+)
      target_label: memory_type
      replacement: ${1}
    - source_labels: ["mcac"]
      regex: jvm\.memory\.(\w+)\.(\w+)
      target_label: __name__
      replacement: mcac_jvm_memory_${2}
    - source_labels: ["mcac"]
      regex: jvm\.memory\.pools\.(\w+)\.(\w+)
      target_label: pool_name
      replacement: ${2}
    - source_labels: ["mcac"]
      regex: jvm\.memory\.pools\.(\w+)\.(\w+)
      target_label: __name__
      replacement: mcac_jvm_memory_pool_${2}
    - source_labels: ["mcac"]
      regex: jvm\.fd\.usage
      target_label: __name__
      replacement: mcac_jvm_fd_usage
    - source_labels: ["mcac"]
      regex: jvm\.buffers\.(\w+)\.(\w+)
      target_label: buffer_type
      replacement: ${1}
    - source_labels: ["mcac"]
      regex: jvm\.buffers\.(\w+)\.(\w+)
      target_label: __name__
      replacement: mcac_jvm_buffer_${2}
    #Append the prom types back to formatted names
    - source_labels: [__name__, "prom_name"]
      regex: (mcac_.*);.*(_micros_bucket|_bucket|_micros_count_total|_count_total|_total|_micros_sum|_sum|_stddev).*
      separator: ;
      target_label: __name__
      replacement: ${1}${2}
    - regex: prom_name
      action: labeldrop

Start your Prometheus server Docker container.

Be sure to change the path in the command below to point to the prometheus.yml file from above.
```
docker run \
    -d \
    -p 9090:9090 \
    -v /path/to/prometheus.yml:/etc/prometheus/prometheus.yml \
    prom/prometheus
```
If your virtual machine is not available from the internet, install a Dynatrace Environment ActiveGate on your Ubuntu VM.
Recommended: Set the group property on the installation.

Enable and configure extension

In Dynatrace Hub, select Azure Managed Instance for Apache Cassandra.
Enable the extension.
Verify that the Prometheus endpoint publishes the Cassandra metrics. Use either of these queries:

{__name__=~"mcac.*"}

http://<Prometheus Server URL>:9090/api/v1/query?query=%7B__name__%3D%7E%22mcac.*%22%7D
Add the endpoint of your Prometheus server to the Extension Monitoring Configuration:

http://<Prometheus Server URL>:9090/api/v1

The <Prometheus Server URL> does not need to be public. If you install your ActiveGate on the same VM or same VNet as the Prometheus server, localhost or a private IP can be used.
Select the ActiveGate group on which to enable this extension.
Add a Monitoring Configuration description and select the Feature Sets of the metrics you'd like to collect.
A dashboard named Azure Managed Instance for Apache Cassandra Overview is provided with the extension.

Metrics

Available metrics are listed below.

Metric metadata and dimensions are available using Data Explorer after the extension is enabled.
See Apache Cassandra Monitoring Documentation for more information about collected metrics.

Cluster node metrics

Metric Name

Metric Key

Description

Storage Load

com.dynatrace.extension.prometheus.azure_cassandra_storage_load

Size, in bytes, of the on-disk data size this node manages.

Storage Exceptions

com.dynatrace.extension.prometheus.azure_cassandra_storage_exceptions.count

Number of internal exceptions caught. In normal operation, this should be zero.

Commit Log Pending Tasks

com.dynatrace.extension.prometheus.azure_cassandra_commit_log_pending_tasks

Number of commit log messages written but yet to be fsync'd.

Commit Log Completed Tasks Total

com.dynatrace.extension.prometheus.azure_cassandra_commit_log_completed_tasks_total.count

Total number of commit log messages written since start/restart.

Buffer Pool Size

com.dynatrace.extension.prometheus.azure_cassandra_buffer_pool_size

Size, in bytes, of the managed buffer pool.

Buffer Pool Misses Total

com.dynatrace.extension.prometheus.azure_cassandra_buffer_pool_misses_total.count

The number of misses in the pool. The higher this is, the more allocations incurred.

Client Connected Native Clients

com.dynatrace.extension.prometheus.azure_cassandra_client_connected_native_clients

Number of clients connected to this node's native protocol server.

Client Auth Failure Total

com.dynatrace.extension.prometheus.azure_cassandra_client_auth_failure_total.count

Number of clients who experience authentication failures.

Client Auth Success Total

com.dynatrace.extension.prometheus.azure_cassandra_client_auth_success_total.count

Number of clients who successfully authenticate.

Storage Total Hints Total

com.dynatrace.extension.prometheus.azure_cassandra_storage_total_hints_total.count

Number of hint messages written to this node since start/restart. Includes one entry for each host to be hinted per hint.

CQL Prepared Statements Executed Total

com.dynatrace.extension.prometheus.azure_cassandra_cql_prepared_statements_executed_total.count

Number of prepared statements executed.

CQL Regular Statements Executed Total

com.dynatrace.extension.prometheus.azure_cassandra_cql_regular_statements_executed_total.count

Number of non-prepared statements executed.

Dropped Messages Total

com.dynatrace.extension.prometheus.azure_cassandra_dropped_messages_total.count

Number of dropped messages.

JVM GC Count

com.dynatrace.extension.prometheus.azure_cassandra_jvm_gc_count.count

Total number of collections that have occurred.

JVM GC Time

com.dynatrace.extension.prometheus.azure_cassandra_jvm_gc_time.count

Approximate accumulated collection elapsed time in milliseconds.

JVM Memory Used

com.dynatrace.extension.prometheus.azure_cassandra_jvm_memory_used

Amount of used memory in bytes.

JVM Memory Usage

func:com.dynatrace.extension.prometheus.azure_cassandra_jvm_memory_usage

Ratio of used memory to maximum memory.

Thread Pools Active Tasks

com.dynatrace.extension.prometheus.azure_cassandra_thread_pools_active_tasks

Number of tasks being actively worked on by this pool.

Thread Pools Total Blocked Tasks Total

com.dynatrace.extension.prometheus.azure_cassandra_thread_pools_total_blocked_tasks_total.count

Number of tasks that were blocked due to queue saturation.

Thread Pools Completed Tasks

com.dynatrace.extension.prometheus.azure_cassandra_thread_pools_completed_tasks

Number of tasks completed.

Client Request Latency Total

com.dynatrace.extension.prometheus.azure_cassandra_client_request_latency_total.count

Latency of client requests.

Client Request Failures Total

com.dynatrace.extension.prometheus.azure_cassandra_client_request_failures_total.count

Number of transaction failures encountered.

Client Request Unavailables Total

com.dynatrace.extension.prometheus.azure_cassandra_client_request_unavailables_total.count

Number of unavailable exceptions encountered.

Cache Hit Rate

func:com.dynatrace.extension.prometheus.azure_cassandra_cache_hit_rate

All-time cache hit rate.

Cache Capacity

com.dynatrace.extension.prometheus.azure_cassandra_cache_capacity

Cache capacity in bytes.

Cache Misses Total

com.dynatrace.extension.prometheus.azure_cassandra_cache_misses_total.count

Total number of cache misses.

Cache Size

com.dynatrace.extension.prometheus.azure_cassandra_cache_size

Total size of occupied cache, in bytes.

Keyspace metrics

Metric Name

Metric Key

Description

Keyspace All Memtables Live Data Size

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_all_memtables_live_data_size

Total amount of live data stored in the memtables (2i and pending flush memtables included) that resides off-heap, excluding any data structure overhead.

Keyspace Bloom Filter Disk Space Used

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_bloom_filter_disk_space_used

Disk space used by bloom filter (in bytes).

Keyspace Live Disk Space Used

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_live_disk_space_used

Disk space used by SSTables belonging to this table (in bytes).

Keyspace Memtable Columns Count

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_memtable_columns_count.gauge

Total number of columns present in the memtable.

Keyspace Memtable Live Data Size

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_memtable_live_data_size

Total amount of live data stored in the memtable, excluding any data structure overhead.

Keyspace Memtable Switch Count

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_memtable_switch_count.gauge

Number of times that flush has resulted in the memtable being switched out.

Keyspace Pending Compaction

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_pending_compaction

Estimated number of compactions remaining to perform.

Keyspace Pending Flushes

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_pending_flushes

Estimated number of flush tasks pending for this table.

Keyspace Read Total Latency Total

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_read_total_latency_total.count

Read latency.

Keyspace Total Disk Space Used

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_total_disk_space_used

Total disk space used by SSTables belonging to this table, including obsolete ones waiting for GC.

Keyspace Write Total Latency Total

com.dynatrace.extension.prometheus.azure_cassandra_keyspace_write_total_latency_total.count

Write Latency.

Table metrics

Metric Name

Metric Key

Description

Table Bloom Filter Disk Space Used

com.dynatrace.extension.prometheus.azure_cassandra_table_bloom_filter_disk_space_used

Disk space used by bloom filter (in bytes).

Table Bloom Filter False Positives

com.dynatrace.extension.prometheus.azure_cassandra_table_bloom_filter_false_positives

Number of false positives on table's bloom filter.

Table Bloom Filter False Ratio

func:com.dynatrace.extension.prometheus.azure_cassandra_table_bloom_filter_false_ratio

False positive ratio of table's bloom filter.

Table Bytes Flushed Total

com.dynatrace.extension.prometheus.azure_cassandra_table_bytes_flushed_total.count

Total number of bytes flushed since server start/restart.

Table Compaction Bytes Written Total

com.dynatrace.extension.prometheus.azure_cassandra_table_compaction_bytes_written_total.count

Total number of bytes compacted since server start/restart.

Table Compression Ratio

func:com.dynatrace.extension.prometheus.azure_cassandra_table_compression_ratio

Current compression ratio for all SSTables.

Table Dropped Mutations Total

com.dynatrace.extension.prometheus.azure_cassandra_table_dropped_mutations_total.count

Number of dropped mutations on this table.

Table Estimated Partition Count

com.dynatrace.extension.prometheus.azure_cassandra_table_estimated_partition_count.gauge

Approximate number of keys in table.

Table Key Cache Hit Rate

func:com.dynatrace.extension.prometheus.azure_cassandra_table_key_cache_hit_rate

Key cache hit rate for this table.

Table Live Disk Space Used Total

com.dynatrace.extension.prometheus.azure_cassandra_table_live_disk_space_used_total

Disk space used by SSTables belonging to this table (in bytes).

Table Live SSTable Count

com.dynatrace.extension.prometheus.azure_cassandra_table_live_ss_table_count.gauge

Number of SSTables on disk for this table.

Table Memtable Columns Count

com.dynatrace.extension.prometheus.azure_cassandra_table_memtable_columns_count.gauge

Total number of columns present in the memtable.

Table Memtable Live Data Size

com.dynatrace.extension.prometheus.azure_cassandra_table_memtable_live_data_size

Total amount of live data stored in the memtable, excluding any data structure overhead.

Table Memtable Switch Count Total

com.dynatrace.extension.prometheus.azure_cassandra_table_memtable_switch_count_total.count

Number of times that flush has resulted in the memtable being switched out.

Table Pending Compactions

com.dynatrace.extension.prometheus.azure_cassandra_table_pending_compactions

Estimate of number of pending compactions for this table.

Table Pending Flushes Total

com.dynatrace.extension.prometheus.azure_cassandra_table_pending_flushes_total.count

Estimate of number of pending flushes for this table.

Table Read Total Latency Total

com.dynatrace.extension.prometheus.azure_cassandra_table_read_total_latency_total.count

Read latency for this table.

Table Row Cache Hit Total

com.dynatrace.extension.prometheus.azure_cassandra_table_row_cache_hit_total.count

Number of table row cache hits.

Table Row Cache Miss Total

com.dynatrace.extension.prometheus.azure_cassandra_table_row_cache_miss_total.count

Number of table row cache misses.

Table Total Disk Space Used Total

com.dynatrace.extension.prometheus.azure_cassandra_table_total_disk_space_used_total

Total disk space used by SSTables belonging to this table, including obsolete ones waiting to for GC.

Table Write Total Latency Total

com.dynatrace.extension.prometheus.azure_cassandra_table_write_total_latency_total.count

Write latency for this table.