CouchBase Monitoring Extension for AppDynamics

Use Case

Couchbase Server is an open source, distributed (shared-nothing architecture) NoSQL document-oriented database that is optimized for interactive applications. This extension allows the user to connect to a specific cluster host and retrieve metrics about the cluster, all the nodes within the cluster and any buckets associated with the nodes.

Prerequisites

  1. Before the extension is installed, the prerequisites mentioned here need to be met. Please do not proceed with the extension installation if the specified prerequisites are not met.
  2. The client created through the extension uses various REST endpoints provided by the CouchBase server to retrieve metrics.
    Please make sure your user account has proper admin role to access all the REST endpoints. "Full" and "Cluster" level roles gives you access to all the REST endpoints.
  3. The extension needs to be able to connect to the CouchBase server in order to collect and send metrics. To do this, you will have to either establish a remote connection in between the extension and the product, or have an agent on the same machine running the product in order for the extension to collect and send the metrics.

Installation

  1. Run 'mvn clean install' from "CouchBaseMonitorRepo"
  2. Unzip the CouchBaseMonitor-<version>.zip from target directory into the "<MachineAgent_Dir>/monitors" directory.
  3. Edit the file config.yml located at <MachineAgent_Dir>/monitors/CouchBaseMonitor The metricPrefix of the extension has to be configured as specified here. Please make sure that the right metricPrefix is chosen based on your machine agent deployment, otherwise this could lead to metrics not being visible in the controller.
  4. Restart the Machine Agent.

Please place the extension in the "monitors" directory of your Machine Agent installation directory. Do not place the extension in the "extensions" directory of your Machine Agent installation directory.

Recommendations

It is recommended that a single CouchBase monitoring extension be used to monitor a single CouchBase cluster.

Configuring the extension using config.yml

Configure the CouchBase monitoring extension by editing the config.yml file in <MACHINE_AGENT_HOME>/monitors/CouchBaseMonitor/

  1. Configure the "tier" under which the metrics need to be reported. This can be done by changing the value of <TIER NAME OR TIER ID> in
    metricPrefix: "Server|Component:<TIER NAME OR TIER ID>|Custom Metrics|CouchBase".

    For example,

    metricPrefix: "Server|Component:Extensions tier|Custom Metrics|CouchBase"
    

More details around metric prefix can be found here.

  1. Configure the CouchBase cluster by specifying the name(required), host(required), port(required), queryPort(required) of any node(server) in the CouchBase cluster, username(only if authentication enabled), password(only if authentication enabled), passwordEncrypted(only if password encryption required).

    For example,

     servers:
       - name: "Cluster1"
         host: "localhost"
         port: "8091"
         queryPort: "8093"
         username: "Administrator"
         password: "password1"
         encryptedPassword: ""
    
  2. Configure the encryptionKey for encryptedPassword(only if password encryption required). See next section for encrypting password.

    For example,

    #Encryption key for Encrypted password.
    encryptionKey: "axcdde43535hdhdgfiniyy576"
    
  3. Configure the controllerInfo section (optional)

    For example,

    controllerInfo:
      username: "username" # Username used for controller login
      account: "customer1" # Accountname in the controller
      password: "password" #  Password for the above username 
      encryptedPassword: "" # Only required if encrypting the password, else leave it empty
    
  4. Configure the metrics section.

    For configuring the metrics, the following properties can be used:

    Property Default value Possible values Description
    alias metric name Any string The substitute name to be used in the metric browser instead of metric name.
    aggregationType "AVERAGE" "AVERAGE", "SUM", "OBSERVATION" Aggregation qualifier
    timeRollUpType "AVERAGE" "AVERAGE", "SUM", "CURRENT" Time roll-up qualifier
    clusterRollUpType "INDIVIDUAL" "INDIVIDUAL", "COLLECTIVE" Cluster roll-up qualifier
    multiplier 1 Any number Value with which the metric needs to be multiplied.
    convert null Any key value map Set of key value pairs that indicates the value to which the metrics need to be transformed. eg: UP:0, DOWN:1
    delta false true, false If enabled, gives the delta values of metrics instead of actual values.

    For example,

    - bandwidth_usage:  #Bandwidth used during replication, measured in bytes per second.
        alias: "bandwidthUsed"
        multiplier: 1
        aggregationType: "SUM"
        timeRollUpType: "CURRENT"
        clusterRollUpType: "INDIVIDUAL"
        delta: true
    - status:
        alias: "status"
        convert:
          "healthy" : 1
          "warmup" : 2
    

    All these metric properties are optional, and the default value shown in the table is applied to the metric(if a property has not been specified) by default.

    There are six categories of metrics i.e cluster, node , bucket, query, xdcr, index. To disable any of these sections, change the include parameter under the section to "false" as follows:

    index:
       include: "false"
       stats:
           - memorySnapshotInterval:
                 alias: "memorySnapshotInterval"
           - stableSnapshotInterval:
                 alias: "stableSnapshotInterval"
           - maxRollbackPoints:
                 alias: "maxRollbackPoints"
    

Metrics

Metric Category: cluster Metrics

Metric Name Description
ram_total Total ram available to cluster (bytes)
ram_quotaUsed Ram quota used by the cluster (bytes)
ram_usedByData Ram used by the data in the cluster (bytes)
ram_quotaTotal Ram quota total for the cluster (bytes)
ram_used Ram used by the cluster (bytes)
hdd_total Total harddrive space available to cluster (bytes)
hdd_used Harddrive space used by the cluster (bytes)
hdd_usedByData Harddrive use by the data in the cluster(bytes)
hdd_quotaTotal Harddrive quota total for the cluster (bytes)
hdd_free Free harddrive space in the cluster (bytes)

Metric Category: nodes Metrics

Metric Name Description
memoryFree Amount of memory free for the node (bytes)
vb_replica_curr_items Number of items/documents that are replicas
couch_docs_data_size Data size of couch documents associated with a node (bytes)
mem_total Total memory available to the node (bytes)
mcdMemoryAllocated Amount of memcached memory allocated (bytes)
mcdMemoryReserved Amount of memcached memory reserved (bytes)
uptime Time during which the node was in operation (sec)
ep_bg_fetched Number of disk fetches performed since server was started
mem_used Memory used by the node (bytes)
memoryTotal Total memory available to the node (bytes)
get_hits Number of get hits
curr_items Number of current items
cmd_get Number of get commands
couch_views_actual_disk_size Amount of disk space occupied by Couch views (bytes)
swap_used Amount of swap space used.(bytes)
cpu_utilization_rate The CPU utilization rate (%)
couch_views_data_size Size of object data for Couch views (bytes)
curr_items_tot Total number of items associated with node
couch_docs_actual_disk_size Amount of disk space used by Couch docs.(bytes)
swap_total Total swap size allocated (bytes)
ops Number of operations performed on Couchbase

Metric Category: buckets Metrics

Metric Name Description
opsPerSec Number of operations per second
rawRAM Amount of raw RAM used by the bucket (bytes)
diskFetches Number of disk fetches
ram Amount of RAM used by the bucket (bytes)
dataUsed Size of user data within buckets of the specified state that are resident in RAM.(%)
memUsed Amount of memory used by the bucket (bytes)
itemCount Number of items associated with the bucket
diskUsed Amount of disk used (bytes)
quotaPercentUsed Percentage of RAM used (for active objects) against the configure bucket size.(%)

Metric Category: query Metrics

Metric Name Description
request.completed.count Number of requests completed
request.active.count Number of active requests
request.per.sec.1min query throughput 1 minute
request.per.sec.5min query throughput 5 minutes
request.per.sec.15min query throughput 15 minutes
request_time.mean Mean time to comlete a request
request_time.median Median time to complete a request
request_time.80percentile 80th percentile query response time
request_time.95percentile 95th percentile query response time
request_time.99percentile 99th percentile query response time
request.prepared.percent percentage of prepared requests

Metric Category: xdcr Metrics

Metric Name Description
bandwidth_usage Bandwidth used during replication, measured in bytes per second
changes_left Number of updates still pending replication
data_replicated Size of data replicated in bytes
docs_checked Number of documents checked for changes
docs_failed_cr_source Number of documents that have failed conflict resolution on the source cluster and not replicated to target cluster
docs_filtered Number of documents that have been filtered out and not replicated to target cluster
docs_latency_wt Weighted average latency for sending replicated changes to destination cluster
docs_opt_repd Number of docs sent optimistically
docs_received_from_dcp Number of documents received from DCP
docs_rep_queue Number of documents in replication queue
docs_written Number of documents written to the destination cluster via xdcr
meta_latency_wt Weighted average time for requesting document metadata. xdcr uses this for conflict resolution prior to sending the document into the replication queue.
num_checkpoints Number of checkpoints issued in replication queue.
num_failedckpts Number of checkpoints failed during replication.
rate_received_from_dcp Number of documents received from DCP per second.
rate_replication Rate of documents being replicated, measured in documents per second.
size_rep_queue Size of replication queue in bytes.
time_committing Seconds elapsed during replication.

Metric Category: index Metrics

Metric Name Description
memorySnapshotInterval How often the indexer creates an in-memory snapshot for querying
stableSnapshotInterval How often the indexer creates a persistent snapshot of recovery
maxRollbackPoints Maximum number of rollback points

Credentials Encryption

Please visit Encryption Guidelines to get detailed instructions on password encryption. The steps in this document will guide you through the whole process.
If you want to use password encryption, please send arguments as connectionProperties. You will have to fill in the encrypted Password and Encryption Key fields in the config but you will also have to give an empty "" value to the password field and the encrypted password will be automatically picked up.

Extensions Workbench

Workbench is an inbuilt feature provided with each extension in order to assist you to fine tune the extension setup before you actually
deploy it on the controller. Please review the following document on How to use the Extensions WorkBench

Troubleshooting

Please follow the steps listed in this troubleshooting-document in order to troubleshoot your issue.
These are a set of common issues that customers might have faced during the installation of the extension.

Contributing

Always feel free to fork and contribute any changes directly here on GitHub.

Version

Name Version
Extension version 2.0.4
CouchBase version tested on 6.5.1
Last Update 18/02/2021
Changelist Changelog

Note: While extensions are maintained and supported by customers under the open-source licensing model, they interact with agents and Controllers that are subject to AppDynamics’ maintenance and support policy. Some extensions have been tested with AppDynamics 4.5.13+ artifacts, but you are strongly recommended against using versions that are no longer supported.

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