Bucket monitoring within the Couchbase Web Console has been updated to show additional detailed information. The following statistic groups are available for Couchbase bucket types.
Summary
The summary section provides a quick overview of the cluster activity. For more information, see Section 6.4.1.1, “Bucket Monitoring — Summary Statistics”.
vBucket Resources
This section provides detailed information on the vBucket resources across the cluster, including the active, replica and pending operations. For more information, see Section 6.4.1.2, “Monitoring vBucket Resources”.
Disk Queues
Disk queues show the activity on the backend disk storage used for persistence within a data bucket. The information displayed shows the active, replica and pending activity. For more information, see Section 6.4.1.3, “Monitoring Disk Queues”.
TAP Queues
The TAP queues section provides information on the activity within the TAP queues across replication, rebalancing and client activity. For more information, see Section 6.4.1.4, “Monitoring TAP Queues”.
XDC Destination
The XDCR Destination section show you statistical information about the Cross Datacenter Replication (XDCR), if XDCR has been configured. For more information on XDCR, see Section 5.8, “Cross Datacenter Replication (XDCR)”. For more information on the available statistics, see Section 6.4.1.6, “Monitoring Outgoing XDCR”.
View Stats
The View Stats section allows you to monitor the statistics for each production view configured within the bucket or system. For more information on the available statistics, see Section 6.4.1.8, “Monitoring View Statistics”.
Top Keys
This shows a list of the top 10 most actively used keys within the selected data bucket.
For Memcached bucket types, the Memcached statistic summary is provided. See Section 6.4.1.5, “Bucket Memcached Buckets”.
The summary section is designed to provide a quick overview of the cluster activity. Each graph (or selected graph) shows information based on the currently selected bucket.
The following graph types are available:
ops per second
The total number of operations per second on this bucket.
cache miss ratio
Ratio of reads per second to this bucket which required a read from disk rather than RAM.
creates per second
Number of new items created in this bucket per second.
updates per second
Number of existing items updated in this bucket per second.
XDCR ops per sec
Number of XDCR related operations per second for this bucket.
disk reads per sec
Number of reads per second from disk for this bucket.
temp OOM per sec
Number of temporary out of memory conditions per second.
gets per second
Number of get operations per second.
sets per second
Number of set operations per second.
deletes per second
Number of delete operations per second.
items
Number of items (documents) stored in the bucket.
disk write queue
Size of the disk write queue.
docs data size
Size of the stored document data.
docs total disk size
Size of the persisted stored document data on disk.
doc fragmentation %
Document fragmentation of persisted data as stored on disk.
XDC replication queue
Size of the XDCR replication queue.
total disk size
Total size of the information for this bucket as stored on disk, including persisted and view index data.
views data size
Size of the view data information.
views total disk size
Size of the view index information as stored on disk.
views fragmentation %
Percentage of fragmentation for a given view index.
view reads per second
Number of view reads per second.
memory used
Amount of memory used for storing the information in this bucket.
high water mark
High water mark for this bucket (based on the configured bucket RAM quota).
low water mark
Low water mark for this bucket (based on the configured bucket RAM quota).
disk update time
Time required to update data on disk.
The vBucket statistics provide information for all vBucket types within the cluster across three different states. Within the statistic display the table of statistics is organized in four columns, showing the Active, Replica and Pending states for each individual statistic. The final column provides the total value for each statistic.
The Active column displays the information for vBuckets within the Active state. The Replica column displays the statistics for vBuckets within the Replica state (i.e. currently being replicated). The Pending columns shows statistics for vBuckets in the Pending state, i.e. while data is being exchanged during rebalancing.
These states are shared across all the following statistics. For example, the graph new items per sec within the Active state column displays the number of new items per second created within the vBuckets that are in the active state.
The individual statistics, one for each state, shown are:
vBuckets
The number of vBuckets within the specified state.
items
Number of items within the vBucket of the specified state.
resident %
Percentage of items within the vBuckets of the specified state that are resident (in RAM).
new items per sec.
Number of new items created in vBuckets within the specified state. Note that new items per second is not valid for the Pending state.
ejections per second
Number of items ejected per second within the vBuckets of the specified state.
user data in RAM
Size of user data within vBuckets of the specified state that are resident in RAM.
metadata in RAM
Size of item metadata within the vBuckets of the specified state that are resident in RAM.
The Disk Queues statistics section displays the information for data being placed into the disk queue. Disk queues are used within Couchbase Server to store the information written to RAM on disk for persistence. Information is displayed for each of the disk queue states, Active, Replica and Pending.
The Active column displays the information for the Disk Queues within the Active state. The Replica column displays the statistics for the Disk Queues within the Replica state (i.e. currently being replicated). The Pending columns shows statistics for the disk Queues in the Pending state, i.e. while data is being exchanged during rebalancing.
These states are shared across all the following statistics. For example, the graph fill rate within the Replica state column displays the number of items being put into the replica disk queue for the selected bucket.
The displayed statistics are:
items
The number of items waiting to be written to disk for this bucket for this state.
fill rate
The number of items per second being added to the disk queue for the corresponding state.
drain rate
Number of items actually written to disk from the disk queue for the corresponding state.
average age
The average age of items (in seconds) within the disk queue for the specified state.
The TAP queues statistics are designed to show information about the TAP queue activity, both internally, between cluster nodes and clients. The statistics information is therefore organized as a table with columns showing the statistics for TAP queues used for replication, rebalancing and clients.
The statistics in this section are detailed below:
TAP senders
Number of TAP queues in this bucket for internal (replica), rebalancing or client connections.
items
Number of items in the corresponding TAP queue for this bucket.
drain rate
Number of items per second being sent over the corresponding TAP queue connections to this bucket.
back-off rate
Number of back-offs per second sent when sending data through the corresponding TAP connection to this bucket.
backfill remaining
Number of items in the backfill queue for the corresponding TAP connection for this bucket.
remaining on disk
Number of items still on disk that need to be loaded in order to service the TAP connection to this bucket.
For Memcached buckets, Web Console displays a separate group of statistics:
The Memcached statistics are:
Operations per sec.
Total operations per second serviced by this bucket
Hit Ratio %
Percentage of get requests served with data from this bucket
Memory bytes used
Total amount of RAM used by this bucket
Items count
Number of items stored in this bucket
RAM evictions per sec.
Number of items per second evicted from this bucket
Sets per sec.
Number of set operations serviced by this bucket
Gets per sec.
Number of get operations serviced by this bucket
Net. bytes TX per sec
Number of bytes per second sent from this bucket
Net. bytes RX per sec.
Number of bytes per second sent into this bucket
Get hits per sec.
Number of get operations per second for data that this bucket contains
Delete hits per sec.
Number of delete operations per second for data that this bucket contains
Incr hits per sec.
Number of increment operations per second for data that this bucket contains
Decr hits per sec.
Number of decrement operations per second for data that this bucket contains
Delete misses per sec.
Number of delete operations per second for data that this bucket does not contain
Decr misses per sec.
Number of decr operations per second for data that this bucket does not contain
Get Misses per sec.
Number of get operations per second for data that this bucket does not contain
Incr misses per sec.
Number of increment operations per second for data that this bucket does not contain
CAS hits per sec.
Number of CAS operations per second for data that this bucket contains
CAS badval per sec.
Number of CAS operations per second using an incorrect CAS ID for data that this bucket contains
CAS misses per sec.
Number of CAS operations per second for data that this bucket does not contain
The Outgoing XDCR shows the XDCR operations that are supporting cross datacenter replication from the current cluster to a destination cluster. For more information on XDCR, see Section 5.8, “Cross Datacenter Replication (XDCR)”.
You can monitor the current status for all active replications in the Ongoing Replications section under the XDCR tab:
The Ongoing Replications section shows the following information:
| Column | Description |
|---|---|
| Bucket | The source bucket on the current cluster that is being replicated. |
| From | Source cluster name. |
| To | Destination cluster name. |
| Status | Current status of replications. |
| When | Indicates when replication occurs. |
The Status column indicates the current state of the replication configuration. Possible include:
Starting Up
The replication process has just started, and the clusters are determining what data needs to be sent from the originatin cluster to the destination cluster.
Replicating
The bucket is currently being replicated and changes to the data stored on the originating cluster are being sent to the destination cluster.
Failed
Replication to the destination cluster has failed. The destination cluster cannot be reached. The replication configuration may need to be deleted and recreated.
Under the Data Buckets tab you can click on
a named Couchbase bucket and find more statistics about
replication for that bucket. Couchbase Web Console displays
statistics for the particular bucket; on this page you can
find two drop-down areas called in the Outgoing
XDCR and Incoming XDCR
Operations. Both provides statistics about ongoing
replication for the particular bucket. Under the
Outgoing XDCR panel if you have multiple
replication streams you will see statistics for each stream.
Under the Outbound XDCR section, you will
see information about replication from this source bucket to a
destination bucket:
Here are the meanings for the outgoing XDCR statistics:
mutations to replicate: shows the items on this source bucket that are awaiting replication.mutations checked: shows the number of documents that have been persisted and checked for replication.mutations replicated: number of documents that have been replicated to the destination bucket.data replicated: size of all item replicatedactive vb reps: number of active replicators which are currently workingwaiting vb reps: number of replicators waiting for items to replicatesecs in replicating: time spent by replicators checking items and waitingsecs in checkpointing: time spent by replicators checkpointing and committing items to a destination clustercheckpoints issued: number of checkpoints that have been issued. This is updated every 30 minutes.checkpoints failed: number of failed checkpoints. These are checkpoints which have been issued by the server but have failed.mutations in queue: number of document mutations that are in the replication queue for XDCRqueue size: size of all documents that are in the XDCR replication queue.
The Incoming XDCR section shows the XDCR operations that are coming into to the current cluster from a remote cluster. For more information on XDCR, see Section 5.8, “Cross Datacenter Replication (XDCR)”.
If a cluster is a destination cluster, you will also see this information in Couchbase Web Console for the specific bucket. When you use XDCR,
gets per sec: shows the number of items on a destination cluster which are being read by a source cluster.sets per sec: shows the number of items on a destination cluster which are being creating or changed by a source cluster.deletes per sec: number of items that have been deleted from a destination bucket by a source cluster.total ops per sec: total gets, sets, or deletes on a destination cluster by a source cluster.
The View statistics show information about individual design documents within the selected bucket. One block of stats will be shown for each production-level design document. For more information on Views, see Chapter 9, Views and Indexes.
The statistics shown are:
data size
Size of the data required for this design document.
disk size
Size of the stored index as stored on disk.
view reads per sec.
Number of read operations per second for this view.