Membase Server incorporates a range of statistics and user interface available through the Data Buckets and Server Nodes that shows overview and detailed information so that administrators can better understand the current state of individual nodes and the cluster as a whole.
The Data Buckets page displays a list of all the configured buckets on your system (of both Membase and memcached types). The page provides a quick overview of your cluser health from the perspective of the configured buckets, rather than whole cluster or individual servers.
The information is shown in the form of a table, as seen in the figure below.
For each bucket, the following information is provided in each column:
Bucket name is the given name for the bucket. Clicking on the bucket name takes you to the individual bucket statistics page. For more information, see Section 4.1.3.3, “Individual Bucket Monitoring”.
Bucket type indicates whether the bucket is a Membase or Memcached bucket.
Bucket Resides On shows how many replicas exist for the given bucket.
RAM Usage/Quota shows the amount of RAM used (for active objects) against the configure bucket size.
Disk Usage shows the amount of disk space in use for active object data storage.
To create a new data bucket, click the . See Section 4.1.3.1, “Creating and Editing Data Buckets” for details on creating new data buckets.
When creating a new data bucket, or editing an existing one, you will be presented with the bucket configuration screen. From here you can set the memory size, access control and other settings, depending on whether you are editing or creating a new bucket, and the bucket type.
Creating a new Bucket
When creating a new bucket, you are presented with the Create Bucket dialog, as shown in the figure below.
Bucket Name
The bucket name. The bucket name can only contain characters in range A-Z, a-z, 0-9 as well as underscore, period, dash and percent symbols.
Bucket Type
Specifies the type of the bucket to be created, either
MemcachedorMembase. See Membase Data Buckets for more information.Access Control
The access control configures the port your clients will use to communicate with the data bucket, and whether the bucket requires a password.
To use the TCP standard port (11211), the first bucket you create can use this port without requiring SASL authentication. For each subsequent bucket, you must specify the password to be used for SASL authentication, and client communication must be made using the binary protocol.
To use a dedicated port, select the dedicate port radio button and enter the port number you want to use. Using a dedicated port supports both the text and binary client protocols, and does not require authentication.
Memory Size
This option specifies the amount of available RAM configured on this server which should be allocated to the default bucket. Note that the allocation is the amount of memory that will be allocated for this bucket on each node, not the total size of the bucket across all nodes.
Replication
For Membase buckets you can enable replication to support multiple replicas of the default bucket across the servers within the cluster. You can configure up to three replicas. Each replica receives copies of all the key/value pairs that are managed by the bucket. If the host machine for a bucket fails, a replica can be promoted to take its place, providing continuous (high-availability) cluster operations in spite of machine failure.
You can disable replication by setting the number of replica copies to zero (0). This will configure the default bucket as local-only and therefore only accessible on this machine.
Once you selected the options for the new bucket, you can click button to create and activate the button within your cluster. You can cancel the bucket creation using the button.
Editing Membase Buckets
You can edit a limited number of settings for an existing Membase bucket:
Access Control, including the standard port/password or custom port settings.
Memory Size can be modified providing you have unallocated space within your Cluster configuration. You can reduce the amount of memory allocated to a bucket if that space is not already in use.
The bucket name cannot be modified.
To delete the configured bucket entirely, click the button.
Editing Memcached Buckets
For Memcached buckets, you can modify the following settings when editing an existing bucket:
Access Control, including the standard port/password or custom port settings.
Memory Size can be modified providing you have unallocated space within your Cluster configuration. You can reduce the amount of memory allocated to a bucket if that space is not already in use.
You can delete the bucket entirely by clicking the button.
You can empty a Memcached bucket of all the cached information that it stores by using the button.
Warning
Using the button removes all the objects stored in the Memcached bucket. Using this button on active Memcached buckets may delete important information.
You can obtain basic information about the status of your data buckets by clicking on the bucket name within the Data Buckets page. The bucket information shows memory size, access, and replica information foe the bucket, as shown in the figure below.
You can edit the bucket information by clicking the bucket name within the bucket information display.
Bucket monitoring within the Membase Web Console has been updated to show additional detailed information. The following statistic groups are available for Membase bucket types.
Summary
The summary section provides a quick overview of the cluster activity. For more information, see Section 4.1.3.3.1, “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 4.1.3.3.2, “Bucket 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 4.1.3.3.3, “Bucket 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 4.1.3.3.4, “Bucket Monitoring — TAP Queues”.
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 static summary is provided. See Section 4.1.3.3.5, “Bucket Monitoring — 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 %
Percentrage 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.
disk reads
Number of reads per second from disk for this bucket.
back-offs per second
Number of 'back-offs' sent per second to clients due to out of memory situations for this bucket.
The vBucket statistics provide information for all vBucket types within the cluster across three different states. Within the statistic display the table of statics 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 news 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:
active vBuckets
The number of vBuckets within the specified state.
active items
Number of items within the vBucket of the specified state.
% resident items
Percentage of items within the vBuckets of the specified state that are resident (in RAM).
new items per second
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 Membase 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, beetween 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.
fill rate
Number of items per second being put into 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 received 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 to service the TAP connection to this bucket.
For Memcached buckets a separate suite of Memcached-specific statistics are displayed.
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