Mongo proxy¶
Fault injection¶
The Mongo proxy filter supports fault injection. See the v1 and v2 API reference for how to configure.
Statistics¶
Every configured MongoDB proxy filter has statistics rooted at mongo.<stat_prefix>. with the following statistics:
| Name | Type | Description |
|---|---|---|
| decoding_error | Counter | Number of MongoDB protocol decoding errors |
| delay_injected | Counter | Number of times the delay is injected |
| op_get_more | Counter | Number of OP_GET_MORE messages |
| op_insert | Counter | Number of OP_INSERT messages |
| op_kill_cursors | Counter | Number of OP_KILL_CURSORS messages |
| op_query | Counter | Number of OP_QUERY messages |
| op_query_tailable_cursor | Counter | Number of OP_QUERY with tailable cursor flag set |
| op_query_no_cursor_timeout | Counter | Number of OP_QUERY with no cursor timeout flag set |
| op_query_await_data | Counter | Number of OP_QUERY with await data flag set |
| op_query_exhaust | Counter | Number of OP_QUERY with exhaust flag set |
| op_query_no_max_time | Counter | Number of queries without maxTimeMS set |
| op_query_scatter_get | Counter | Number of scatter get queries |
| op_query_multi_get | Counter | Number of multi get queries |
| op_query_active | Gauge | Number of active queries |
| op_reply | Counter | Number of OP_REPLY messages |
| op_reply_cursor_not_found | Counter | Number of OP_REPLY with cursor not found flag set |
| op_reply_query_failure | Counter | Number of OP_REPLY with query failure flag set |
| op_reply_valid_cursor | Counter | Number of OP_REPLY with a valid cursor |
| cx_destroy_local_with_active_rq | Counter | Connections destroyed locally with an active query |
| cx_destroy_remote_with_active_rq | Counter | Connections destroyed remotely with an active query |
| cx_drain_close | Counter | Connections gracefully closed on reply boundaries during server drain |
Scatter gets¶
Envoy defines a scatter get as any query that does not use an _id field as a query parameter. Envoy looks in both the top level document as well as within a $query field for _id.
Multi gets¶
Envoy defines a multi get as any query that does use an _id field as a query parameter, but where _id is not a scalar value (i.e., a document or an array). Envoy looks in both the top level document as well as within a $query field for _id.
$comment parsing¶
If a query has a top level $comment field (typically in addition to a $query field), Envoy will parse it as JSON and look for the following structure:
{
"callingFunction": "..."
}
- callingFunction
- (required, string) the function that made the query. If available, the function will be used in callsite query statistics.
Per command statistics¶
The MongoDB filter will gather statistics for commands in the mongo.<stat_prefix>.cmd.<cmd>. namespace.
| Name | Type | Description |
|---|---|---|
| total | Counter | Number of commands |
| reply_num_docs | Histogram | Number of documents in reply |
| reply_size | Histogram | Size of the reply in bytes |
| reply_time_ms | Histogram | Command time in milliseconds |
Per collection query statistics¶
The MongoDB filter will gather statistics for queries in the mongo.<stat_prefix>.collection.<collection>.query. namespace.
| Name | Type | Description |
|---|---|---|
| total | Counter | Number of queries |
| scatter_get | Counter | Number of scatter gets |
| multi_get | Counter | Number of multi gets |
| reply_num_docs | Histogram | Number of documents in reply |
| reply_size | Histogram | Size of the reply in bytes |
| reply_time_ms | Histogram | Query time in milliseconds |
Per collection and callsite query statistics¶
If the application provides the calling function in the $comment field, Envoy will generate per callsite statistics. These statistics match the per collection statistics but are found in the mongo.<stat_prefix>.collection.<collection>.callsite.<callsite>.query. namespace.
Runtime¶
The Mongo proxy filter supports the following runtime settings:
- mongo.connection_logging_enabled
- % of connections that will have logging enabled. Defaults to 100. This allows only a % of connections to have logging, but for all messages on those connections to be logged.
- mongo.proxy_enabled
- % of connections that will have the proxy enabled at all. Defaults to 100.
- mongo.logging_enabled
- % of messages that will be logged. Defaults to 100. If less than 100, queries may be logged without replies, etc.
- mongo.mongo.drain_close_enabled
- % of connections that will be drain closed if the server is draining and would otherwise attempt a drain close. Defaults to 100.
- mongo.fault.fixed_delay.percent
- Probability of an eligible MongoDB operation to be affected by the injected fault when there is no active fault. Defaults to the percent specified in the config.
- mongo.fault.fixed_delay.duration_ms
- The delay duration in milliseconds. Defaults to the duration_ms specified in the config.
Access log format¶
The access log format is not customizable and has the following layout:
{"time": "...", "message": "...", "upstream_host": "..."}
- time
- System time that complete message was parsed, including milliseconds.
- message
- Textual expansion of the message. Whether the message is fully expanded depends on the context. Sometimes summary data is presented to avoid extremely large log sizes.
- upstream_host
- The upstream host that the connection is proxying to, if available. This is populated if the filter is used along with the TCP proxy filter.