DCP stats
Statistics for Database Change Protocol (DCP) are obtained via the CLI with
the cbstats tool.
The following table shows the commands you
can use with the cbstats tool to retrieve DCP statistics:
| Command | Description |
|---|---|
| dcp | Retrieves connections specific to statistics. |
| dcpagg | Retrieves statistics that are logically grouped and aggregated together by prefixes. |
| failovers | Retrieves vBucket failover logs. |
Syntax
Use the following command syntax for DCP-related cbstats requests:
cbstats HOST:11210 dcp
cbstats HOST:11210 dcpagg
cbstats HOST:11210 failovers
Example: request all DCP statistics
The following example shows a cbstats request for all DCP-related statistics.
# ./cbstats 10.5.2.54:11210 dcp
Here's some output from the command. The output is quite lengthy, so this sample is truncated.
ep_dcp_count: 6
ep_dcp_items_remaining: 0
ep_dcp_items_sent: 0
ep_dcp_producer_count: 3
ep_dcp_queue_backfillremaining: 0
ep_dcp_queue_fill: 0
ep_dcp_total_bytes: 6630
ep_dcp_total_queue: 0
eq_dcpq:replication:[email protected]>[email protected]:default:connected: true
eq_dcpq:replication:[email protected]>[email protected]:default:created: 1168
eq_dcpq:replication:[email protected]>[email protected]:default:pending_disconnect: false
eq_dcpq:replication:[email protected]>[email protected]:default:reserved: true
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_buffer_bytes: 0
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_buffer_items: 0
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_cur_snapshot_type: none
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_end_seqno: 18446744073709551615
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_flags: 0
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_items_ready: false
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_last_received_seqno: 0
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_opaque: 73
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_snap_end_seqno: 0
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_snap_start_seqno: 0
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_start_seqno: 0
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_state: reading
eq_dcpq:replication:[email protected]>[email protected]:default:stream_100_vb_uuid: 122364695596024
...
Example: request aggregated DCP statistics
The following example shows a cbstats request for a set of aggregated DCP statistics:
# ./cbstats 10.5.2.54:11210 dcpagg
Here's the output from the command:
:total:backoff: 0
:total:count: 6
:total:items_remaining: 0
:total:items_sent: 0
:total:producer_count: 3
:total:total_backlog_size: 0
:total:total_bytes: 6630
replication:backoff: 0
replication:count: 6
replication:items_remaining: 0
replication:items_sent: 0
replication:producer_count: 3
replication:total_backlog_size: 0
replication:total_bytes: 6630
Example: request failover logs
The following example shows a cbstats request for failover logs. The lengthy output of the command is truncated.
# cbstats 10.5.2.54:11210 failovers
Here's some output from the command. The output is quite lengthy, so this sample is truncated.
vb_1000:0:id: 101754288503529
vb_1000:0:seq: 0
vb_1000:num_entries: 1
...
DCP statistics by connection type
DCP provides statistics for consumer, producer, and notifier connection types. The following tables describe the available consumer, producer, and notifier connection statistics. Each connection type has a group of statistics that apply to the connection overall and a group of statistics that apply to the individual streams in the connections.
The identifier for each DCP statistic begins with the string ep_dcpq: followed by a unique client_id and another colon. For example, if your client is named slave1, the identifier for the DCP statistic named created is ep_dcpq:slave1:created.
| Name | Description |
|---|---|
| connected | True if this client is connected |
| created | Creation time of the DCP connection |
| pending_disconnect | True if we’re hanging up on this client |
| reserved | True if the DCP stream is reserved |
| supports_ack | True if the connection use flow control |
| total_acked_bytes | The amount of bytes that the consumer has acknowledged |
| type | The connection type (producer, consumer, or notifier) |
| Name | Description |
|---|---|
| buffer_bytes | The amount of unprocessed bytes |
| buffer_items | The amount of unprocessed items |
| end_seqno | The sequence number where this stream should end |
| flags | The flags used to create this stream |
| items_ready | Whether the stream has messages ready to send |
| opaque | The unique stream identifier |
| snap_end_seqno | The start sequence number of the last snapshot received |
| snap_start_seqno | The end sequence number of the last snapshot received |
| start_seqno | The start sequence number used to create this stream |
| state | The stream state (pending, reading, or dead) |
| vb_uuid | The vBucket UUID used to create this stream |
| Name | Description |
|---|---|
| bytes_sent | The amount of unacknowledged bytes sent to the consumer |
| connected | True if this client is connected |
| created | Creation time for the DCP connection |
| flow_control | True if the connection uses flow control |
| items_remaining | The amount of items remaining to be sent |
| items_sent | The amount of items already sent to the consumer |
| last_sent_time | The maximum amount of bytes that can be sent without receiving an acknowledgment from the consumer |
| noop_enabled | Indicates whether this connection sends noops |
| noop_wait | Indicates whether this connection is waiting for a noop response from the consumer |
| pending_disconnect | True if we’re hanging up on this client |
| reserved | True if the DCP stream is reserved |
| supports_ack | True if the connection uses flow control |
| total_acked_bytes | The amount of bytes that have been acknowledged by the consumer when flow control is enabled |
| total_bytes_sent | The amount of bytes already sent to the consumer |
| type | The connection type (producer, consumer, or notifier) |
| unacked_bytes | The amount of bytes the consumer has not acknowledged |
| Name | Description |
|---|---|
| backfilled | The amount of items sent from disk |
| cur_snapshot_end | The end sequence number of the current snapshot being received |
| cur_snapshot_start | The start sequence number of the current snapshot being received |
| cur_snapshot_type | The type of the current snapshot being received |
| end_seqno | The sequence number of the last mutation to send |
| flags | The flags supplied in the stream request |
| items_ready | Whether the stream has items ready to send |
| last_sent_seqno | The last sequence number sent by this stream |
| memory | The amount of items sent from memory |
| opaque | The unique stream identifier |
| snap_end_seqno | The last snapshot end sequence number (used if a consumer is resuming a stream) |
| snap_start_seqno | The last snapshot start sequence number (used if a consumer is resuming a stream) |
| start_seqno | The sequence number to start sending mutations from |
| state | The stream state (pending, backfilling, in-memory, takeover-send, takeover-wait, or dead) |
| vb_uuid | The vBucket UUID used in the stream request |
Aggregated DCP statistics
DCP provides aggregated statistics that logically group the DCP statistics together by prefixes. For example, if all your DCP connections started with the string xdcr: or replication:, you could use the command cbstats dcpagg : to request statistics grouped by everything before the first colon character, giving you a set for xdcr: statistics and a set for replication: statistics.
The following table describes the aggregated DCP statistics.
| Name | Description |
|---|---|
| [prefix]:count | Number of connections matching this prefix |
| [prefix]:producer_count | Total producer connections with this prefix |
| [prefix]:items_sent | Total items sent with this prefix |
| [prefix]:items_remaining | Total items remaining to be sent with this prefix |
| [prefix]:total_bytes | Total number of bytes sent with this prefix |
| [prefix]:total_backlog_size | Total backfill items remaining to be sent with this prefix |