ClickHouse
Deliver log data to the ClickHouse database
Requirements
>= 1.1.54378
is required.Configuration
Example configurations
{
"sinks": {
"my_sink_id": {
"type": "clickhouse",
"inputs": [
"my-source-or-transform-id"
],
"endpoint": "http://localhost:8123",
"table": "mytable"
}
}
}
[sinks.my_sink_id]
type = "clickhouse"
inputs = [ "my-source-or-transform-id" ]
endpoint = "http://localhost:8123"
table = "mytable"
sinks:
my_sink_id:
type: clickhouse
inputs:
- my-source-or-transform-id
endpoint: http://localhost:8123
table: mytable
{
"sinks": {
"my_sink_id": {
"type": "clickhouse",
"inputs": [
"my-source-or-transform-id"
],
"compression": "gzip",
"database": "mydatabase",
"endpoint": "http://localhost:8123",
"format": "json_each_row",
"table": "mytable"
}
}
}
[sinks.my_sink_id]
type = "clickhouse"
inputs = [ "my-source-or-transform-id" ]
compression = "gzip"
database = "mydatabase"
endpoint = "http://localhost:8123"
format = "json_each_row"
table = "mytable"
sinks:
my_sink_id:
type: clickhouse
inputs:
- my-source-or-transform-id
compression: gzip
database: mydatabase
endpoint: http://localhost:8123
format: json_each_row
table: mytable
acknowledgements
optional objectControls how acknowledgements are handled for this sink.
See End-to-end Acknowledgements for more information on how event acknowledgement is handled.
acknowledgements.enabled
optional boolWhether or not end-to-end acknowledgements are enabled.
When enabled for a sink, any source connected to that sink, where the source supports end-to-end acknowledgements as well, waits for events to be acknowledged by all connected sinks before acknowledging them at the source.
Enabling or disabling acknowledgements at the sink level takes precedence over any global
acknowledgements
configuration.
auth
optional objectConfiguration of the authentication strategy for HTTP requests.
HTTP authentication should be used with HTTPS only, as the authentication credentials are passed as an HTTP header without any additional encryption beyond what is provided by the transport itself.
auth.password
required string literalstrategy = "basic"
auth.strategy
required string literal enumOption | Description |
---|---|
basic | Basic authentication. The username and password are concatenated and encoded via base64. |
bearer | Bearer authentication. The bearer token value (OAuth2, JWT, etc.) is passed as-is. |
batch
optional objectbatch.max_bytes
optional uintThe maximum size of a batch that is processed by a sink.
This is based on the uncompressed size of the batched events, before they are serialized/compressed.
1e+07
(bytes)batch.max_events
optional uintbatch.timeout_secs
optional float1
(seconds)buffer
optional objectConfigures the buffering behavior for this sink.
More information about the individual buffer types, and buffer behavior, can be found in the Buffering Model section.
buffer.max_events
optional uinttype = "memory"
500
buffer.max_size
required uintThe maximum size of the buffer on disk.
Must be at least ~256 megabytes (268435488 bytes).
type = "disk"
buffer.type
optional string literal enumOption | Description |
---|---|
disk | Events are buffered on disk. This is less performant, but more durable. Data that has been synchronized to disk will not be lost if Vector is restarted forcefully or crashes. Data is synchronized to disk every 500ms. |
memory | Events are buffered in memory. This is more performant, but less durable. Data will be lost if Vector is restarted forcefully or crashes. |
memory
buffer.when_full
optional string literal enumOption | Description |
---|---|
block | Wait for free space in the buffer. This applies backpressure up the topology, signalling that sources should slow down the acceptance/consumption of events. This means that while no data is lost, data will pile up at the edge. |
drop_newest | Drops the event instead of waiting for free space in buffer. The event will be intentionally dropped. This mode is typically used when performance is the highest priority, and it is preferable to temporarily lose events rather than cause a slowdown in the acceptance/consumption of events. |
block
compression
optional string literal enumCompression configuration.
All compression algorithms use the default compression level unless otherwise specified.
gzip
database
optional string templatedate_time_best_effort
optional booldate_time_input_format
to best_effort
, allowing ClickHouse to properly parse RFC3339/ISO 8601.false
encoding
optional objectencoding.except_fields
optional [string]encoding.only_fields
optional [string]encoding.timestamp_format
optional string literal enumOption | Description |
---|---|
rfc3339 | Represent the timestamp as a RFC 3339 timestamp. |
unix | Represent the timestamp as a Unix timestamp. |
unix_float | Represent the timestamp as a Unix timestamp in floating point. |
unix_ms | Represent the timestamp as a Unix timestamp in milliseconds. |
unix_ns | Represent the timestamp as a Unix timestamp in nanoseconds. |
unix_us | Represent the timestamp as a Unix timestamp in microseconds |
endpoint
required string literalformat
optional string literal enumData format.
The format to parse input data.
Option | Description |
---|---|
json_as_object | JSONAsObject. |
json_as_string | JSONAsString. |
json_each_row | JSONEachRow. |
json_each_row
healthcheck
optional objecthealthcheck.enabled
optional booltrue
inputs
required [string]A list of upstream source or transform IDs.
Wildcards (*
) are supported.
See configuration for more info.
insert_random_shard
optional boolinsert_distributed_one_random_shard
, allowing ClickHouse to insert data into a random shard when using Distributed Table Engine.false
proxy
optional objectProxy configuration.
Configure to proxy traffic through an HTTP(S) proxy when making external requests.
Similar to common proxy configuration convention, you can set different proxies to use based on the type of traffic being proxied, as well as set specific hosts that should not be proxied.
proxy.http
optional string literalProxy endpoint to use when proxying HTTP traffic.
Must be a valid URI string.
proxy.https
optional string literalProxy endpoint to use when proxying HTTPS traffic.
Must be a valid URI string.
proxy.no_proxy
optional [string]A list of hosts to avoid proxying.
Multiple patterns are allowed:
Pattern | Example match |
---|---|
Domain names | example.com matches requests to example.com |
Wildcard domains | .example.com matches requests to example.com and its subdomains |
IP addresses | 127.0.0.1 matches requests to 127.0.0.1 |
CIDR blocks | 192.168.0.0/16 matches requests to any IP addresses in this range |
Splat | * matches all hosts |
request
optional objectMiddleware settings for outbound requests.
Various settings can be configured, such as concurrency and rate limits, timeouts, retry behavior, etc.
Note that the retry backoff policy follows the Fibonacci sequence.
request.adaptive_concurrency
optional objectConfiguration of adaptive concurrency parameters.
These parameters typically do not require changes from the default, and incorrect values can lead to meta-stable or unstable performance and sink behavior. Proceed with caution.
request.adaptive_concurrency.decrease_ratio
optional floatThe fraction of the current value to set the new concurrency limit when decreasing the limit.
Valid values are greater than 0
and less than 1
. Smaller values cause the algorithm to scale back rapidly
when latency increases.
Note that the new limit is rounded down after applying this ratio.
0.9
request.adaptive_concurrency.ewma_alpha
optional floatThe weighting of new measurements compared to older measurements.
Valid values are greater than 0
and less than 1
.
ARC uses an exponentially weighted moving average (EWMA) of past RTT measurements as a reference to compare with the current RTT. Smaller values cause this reference to adjust more slowly, which may be useful if a service has unusually high response variability.
0.4
request.adaptive_concurrency.initial_concurrency
optional uintThe initial concurrency limit to use. If not specified, the initial limit will be 1 (no concurrency).
It is recommended to set this value to your service’s average limit if you’re seeing that it takes a
long time to ramp up adaptive concurrency after a restart. You can find this value by looking at the
adaptive_concurrency_limit
metric.
1
request.adaptive_concurrency.max_concurrency_limit
optional uintThe maximum concurrency limit.
The adaptive request concurrency limit will not go above this bound. This is put in place as a safeguard.
200
request.adaptive_concurrency.rtt_deviation_scale
optional floatScale of RTT deviations which are not considered anomalous.
Valid values are greater than or equal to 0
, and we expect reasonable values to range from 1.0
to 3.0
.
When calculating the past RTT average, we also compute a secondary “deviation” value that indicates how variable those values are. We use that deviation when comparing the past RTT average to the current measurements, so we can ignore increases in RTT that are within an expected range. This factor is used to scale up the deviation to an appropriate range. Larger values cause the algorithm to ignore larger increases in the RTT.
2.5
request.concurrency
optional string literal enum uintConfiguration for outbound request concurrency.
This can be set either to one of the below enum values or to a positive integer, which denotes a fixed concurrency limit.
Option | Description |
---|---|
adaptive | Concurrency will be managed by Vector’s Adaptive Request Concurrency feature. |
none | A fixed concurrency of 1. Only one request can be outstanding at any given time. |
adaptive
request.rate_limit_duration_secs
optional uintrate_limit_num
option.1
(seconds)request.rate_limit_num
optional uintrate_limit_duration_secs
time window.9.223372036854776e+18
(requests)request.retry_attempts
optional uint9.223372036854776e+18
(retries)request.retry_initial_backoff_secs
optional uintThe amount of time to wait before attempting the first retry for a failed request.
After the first retry has failed, the fibonacci sequence is used to select future backoffs.
1
(seconds)request.retry_jitter_mode
optional string literal enumOption | Description |
---|---|
Full | Full jitter. The random delay is anywhere from 0 up to the maximum current delay calculated by the backoff strategy. Incorporating full jitter into your backoff strategy can greatly reduce the likelihood of creating accidental denial of service (DoS) conditions against your own systems when many clients are recovering from a failure state. |
None | No jitter. |
Full
request.retry_max_duration_secs
optional uint30
(seconds)request.timeout_secs
optional uintThe time a request can take before being aborted.
Datadog highly recommends that you do not lower this value below the service’s internal timeout, as this could create orphaned requests, pile on retries, and result in duplicate data downstream.
60
(seconds)skip_unknown_fields
optional boolinput_format_skip_unknown_fields
, allowing ClickHouse to discard fields not present in the table schema.false
table
required string templatetls
optional objecttls.alpn_protocols
optional [string]Sets the list of supported ALPN protocols.
Declare the supported ALPN protocols, which are used during negotiation with peer. They are prioritized in the order that they are defined.
tls.ca_file
optional string literalAbsolute path to an additional CA certificate file.
The certificate must be in the DER or PEM (X.509) format. Additionally, the certificate can be provided as an inline string in PEM format.
tls.crt_file
optional string literalAbsolute path to a certificate file used to identify this server.
The certificate must be in DER, PEM (X.509), or PKCS#12 format. Additionally, the certificate can be provided as an inline string in PEM format.
If this is set, and is not a PKCS#12 archive, key_file
must also be set.
tls.key_file
optional string literalAbsolute path to a private key file used to identify this server.
The key must be in DER or PEM (PKCS#8) format. Additionally, the key can be provided as an inline string in PEM format.
tls.key_pass
optional string literalPassphrase used to unlock the encrypted key file.
This has no effect unless key_file
is set.
tls.verify_certificate
optional boolEnables certificate verification. For components that create a server, this requires that the client connections have a valid client certificate. For components that initiate requests, this validates that the upstream has a valid certificate.
If enabled, certificates must not be expired and must be issued by a trusted issuer. This verification operates in a hierarchical manner, checking that the leaf certificate (the certificate presented by the client/server) is not only valid, but that the issuer of that certificate is also valid, and so on until the verification process reaches a root certificate.
Do NOT set this to false
unless you understand the risks of not verifying the validity of certificates.
tls.verify_hostname
optional boolEnables hostname verification.
If enabled, the hostname used to connect to the remote host must be present in the TLS certificate presented by the remote host, either as the Common Name or as an entry in the Subject Alternative Name extension.
Only relevant for outgoing connections.
Do NOT set this to false
unless you understand the risks of not verifying the remote hostname.
Telemetry
Metrics
linkbuffer_byte_size
gaugebuffer_discarded_events_total
counterbuffer_events
gaugebuffer_received_event_bytes_total
counterbuffer_received_events_total
counterbuffer_sent_event_bytes_total
counterbuffer_sent_events_total
countercomponent_discarded_events_total
counterfilter
transform, or false if due to an error.component_errors_total
countercomponent_received_event_bytes_total
countercomponent_received_events_count
histogramA histogram of the number of events passed in each internal batch in Vector’s internal topology.
Note that this is separate than sink-level batching. It is mostly useful for low level debugging performance issues in Vector due to small internal batches.
component_received_events_total
countercomponent_sent_bytes_total
countercomponent_sent_event_bytes_total
countercomponent_sent_events_total
counterutilization
gaugeHow it works
Buffers and batches
This component buffers & batches data as shown in the diagram above. You’ll notice that Vector treats these concepts differently, instead of treating them as global concepts, Vector treats them as sink specific concepts. This isolates sinks, ensuring services disruptions are contained and delivery guarantees are honored.
Batches are flushed when 1 of 2 conditions are met:
- The batch age meets or exceeds the configured
timeout_secs
. - The batch size meets or exceeds the configured
max_bytes
ormax_events
.
Buffers are controlled via the buffer.*
options.
Health checks
Require health checks
If you’d like to exit immediately upon a health check failure, you can pass the
--require-healthy
flag:
vector --config /etc/vector/vector.yaml --require-healthy
Disable health checks
healthcheck
option to
false
.Rate limits & adaptive concurrency
Adaptive Request Concurrency (ARC)
Adaptive Request Concurrency is a feature of Vector that does away with static concurrency limits and automatically optimizes HTTP concurrency based on downstream service responses. The underlying mechanism is a feedback loop inspired by TCP congestion control algorithms. Checkout the announcement blog post,
We highly recommend enabling this feature as it improves performance and reliability of Vector and the systems it communicates with. As such, we have made it the default, and no further configuration is required.
Static concurrency
If Adaptive Request Concurrency is not for you, you can manually set static concurrency
limits by specifying an integer for request.concurrency
:
sinks:
my-sink:
request:
concurrency: 10
Rate limits
In addition to limiting request concurrency, you can also limit the overall request
throughput via the request.rate_limit_duration_secs
and request.rate_limit_num
options.
sinks:
my-sink:
request:
rate_limit_duration_secs: 1
rate_limit_num: 10
These will apply to both adaptive
and fixed request.concurrency
values.
Retry policy
request.retry_attempts
and
request.retry_backoff_secs
options.Transport Layer Security (TLS)
tls.*
options and/or via an
OpenSSL configuration file. The file location defaults to
/usr/local/ssl/openssl.cnf
or can be specified with the OPENSSL_CONF
environment variable.