feat(router): add best_of parameter (#117)

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OlivierDehaene 2023-03-09 15:30:54 +01:00 committed by GitHub
parent e8bfe199ba
commit 55bd4fed7d
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7 changed files with 365 additions and 115 deletions

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@ -210,13 +210,63 @@
},
"components": {
"schemas": {
"BestOfSequence": {
"type": "object",
"required": [
"generated_text",
"finish_reason",
"generated_tokens",
"prefill",
"tokens"
],
"properties": {
"finish_reason": {
"$ref": "#/components/schemas/FinishReason"
},
"generated_text": {
"type": "string",
"example": "test"
},
"generated_tokens": {
"type": "integer",
"format": "int32",
"example": 1
},
"prefill": {
"type": "array",
"items": {
"$ref": "#/components/schemas/PrefillToken"
}
},
"seed": {
"type": "integer",
"format": "int64",
"example": 42,
"nullable": true
},
"tokens": {
"type": "array",
"items": {
"$ref": "#/components/schemas/Token"
}
}
}
},
"Details": {
"type": "object",
"required": [
"finish_reason",
"generated_tokens"
"generated_tokens",
"prefill",
"tokens"
],
"properties": {
"best_of_sequences": {
"type": "array",
"items": {
"$ref": "#/components/schemas/BestOfSequence"
}
},
"finish_reason": {
"$ref": "#/components/schemas/FinishReason"
},
@ -234,7 +284,8 @@
"seed": {
"type": "integer",
"format": "int64",
"example": 42
"example": 42,
"nullable": true
},
"tokens": {
"type": "array",
@ -247,11 +298,15 @@
"ErrorResponse": {
"type": "object",
"required": [
"error"
"error",
"error_type"
],
"properties": {
"error": {
"type": "string"
},
"error_type": {
"type": "string"
}
}
},
@ -266,6 +321,13 @@
"GenerateParameters": {
"type": "object",
"properties": {
"best_of": {
"type": "integer",
"default": "null",
"example": 1,
"nullable": true,
"exclusiveMinimum": 0.0
},
"details": {
"type": "boolean",
"default": "true"
@ -292,12 +354,17 @@
},
"return_full_text": {
"type": "boolean",
"default": "None",
"example": false
"default": "null",
"example": false,
"nullable": true
},
"seed": {
"type": "integer",
"format": "int64"
"format": "int64",
"default": "null",
"example": "null",
"nullable": true,
"exclusiveMinimum": 0.0
},
"stop": {
"type": "array",
@ -334,6 +401,21 @@
"maximum": 1.0,
"exclusiveMinimum": 0.0
},
"truncate": {
"type": "integer",
"default": "null",
"example": "null",
"nullable": true
},
"typical_p": {
"type": "number",
"format": "float",
"default": "null",
"example": 0.95,
"nullable": true,
"maximum": 1.0,
"exclusiveMinimum": 0.0
},
"watermark": {
"type": "boolean",
"default": "false",
@ -414,7 +496,8 @@
"seed": {
"type": "integer",
"format": "int64",
"example": 42
"example": 42,
"nullable": true
}
}
},

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@ -31,6 +31,8 @@ struct Args {
quantize: bool,
#[clap(default_value = "128", long, env)]
max_concurrent_requests: usize,
#[clap(default_value = "2", long, env)]
max_best_of: usize,
#[clap(default_value = "4", long, env)]
max_stop_sequences: usize,
#[clap(default_value = "1000", long, env)]
@ -86,6 +88,7 @@ fn main() -> ExitCode {
num_shard,
quantize,
max_concurrent_requests,
max_best_of,
max_stop_sequences,
max_input_length,
max_total_tokens,
@ -363,6 +366,8 @@ fn main() -> ExitCode {
"text-generation-router".to_string(),
"--max-concurrent-requests".to_string(),
max_concurrent_requests.to_string(),
"--max-best-of".to_string(),
max_best_of.to_string(),
"--max-stop-sequences".to_string(),
max_stop_sequences.to_string(),
"--max-input-length".to_string(),

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@ -2,6 +2,7 @@
use crate::validation::{Validation, ValidationError};
use crate::{Entry, Queue, Token};
use crate::{GenerateRequest, PrefillToken};
use futures::future::try_join_all;
use nohash_hasher::IntMap;
use std::sync::Arc;
use text_generation_client::{
@ -177,6 +178,43 @@ impl Infer {
Err(err)
}
}
/// Add best_of new requests to the queue and return a InferResponse of the sequence with
/// the highest log probability per token
#[instrument(skip(self))]
pub(crate) async fn generate_best_of(
&self,
request: GenerateRequest,
best_of: usize,
) -> Result<(InferResponse, Vec<InferResponse>), InferError> {
// validate best_of parameter separately
let best_of = self.validation.validate_best_of(best_of)?;
// create multiple generate requests
let mut infer_responses: Vec<InferResponse> =
try_join_all((0..best_of).map(|_| self.generate(request.clone()))).await?;
// get the sequence with the highest log probability per token
let mut max_index = 0;
let mut max_logprob: f32 = f32::MIN;
for (i, response) in infer_responses.iter().enumerate() {
// mean logprobs of the generated tokens
let sequence_logprob = response
.tokens
.iter()
.map(|token| token.logprob)
.sum::<f32>()
/ response.tokens.len() as f32;
// set best sequence
if sequence_logprob > max_logprob {
max_index = i;
max_logprob = sequence_logprob;
}
}
let best_response = infer_responses.remove(max_index);
Ok((best_response, infer_responses))
}
}
/// Batching logic

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@ -12,6 +12,9 @@ use validation::Validation;
#[derive(Clone, Debug, Deserialize, ToSchema)]
pub(crate) struct GenerateParameters {
#[serde(default)]
#[schema(exclusive_minimum = 0, nullable = true, default = "null", example = 1)]
pub best_of: Option<usize>,
#[serde(default)]
#[schema(
exclusive_minimum = 0.0,
@ -56,13 +59,13 @@ pub(crate) struct GenerateParameters {
#[schema(exclusive_minimum = 0, exclusive_maximum = 512, default = "20")]
pub max_new_tokens: u32,
#[serde(default)]
#[schema(default = "null", example = false)]
#[schema(nullable = true, default = "null", example = false)]
pub return_full_text: Option<bool>,
#[serde(default)]
#[schema(inline, max_items = 4, example = json ! (["photographer"]))]
pub stop: Vec<String>,
#[serde(default)]
#[schema(default = "null", example = "null")]
#[schema(nullable = true, default = "null", example = "null")]
pub truncate: Option<usize>,
#[serde(default)]
#[schema(default = "false", example = true)]
@ -71,6 +74,12 @@ pub(crate) struct GenerateParameters {
#[schema(default = "true")]
pub details: bool,
#[serde(default)]
#[schema(
exclusive_minimum = 0,
nullable = true,
default = "null",
example = "null"
)]
pub seed: Option<u64>,
}
@ -80,6 +89,7 @@ fn default_max_new_tokens() -> u32 {
fn default_parameters() -> GenerateParameters {
GenerateParameters {
best_of: None,
temperature: None,
repetition_penalty: None,
top_k: None,
@ -158,16 +168,32 @@ pub(crate) enum FinishReason {
StopSequence,
}
#[derive(Serialize, ToSchema)]
pub(crate) struct BestOfSequence {
#[schema(example = "test")]
pub generated_text: String,
#[schema(example = "length")]
pub finish_reason: FinishReason,
#[schema(example = 1)]
pub generated_tokens: u32,
#[schema(nullable = true, example = 42)]
pub seed: Option<u64>,
pub prefill: Vec<PrefillToken>,
pub tokens: Vec<Token>,
}
#[derive(Serialize, ToSchema)]
pub(crate) struct Details {
#[schema(example = "length")]
pub finish_reason: FinishReason,
#[schema(example = 1)]
pub generated_tokens: u32,
#[schema(example = 42)]
#[schema(nullable = true, example = 42)]
pub seed: Option<u64>,
pub prefill: Vec<PrefillToken>,
pub tokens: Vec<Token>,
#[serde(skip_serializing_if = "Option::is_none")]
pub best_of_sequences: Option<Vec<BestOfSequence>>,
}
#[derive(Serialize, ToSchema)]
@ -184,7 +210,7 @@ pub(crate) struct StreamDetails {
pub finish_reason: FinishReason,
#[schema(example = 1)]
pub generated_tokens: u32,
#[schema(example = 42)]
#[schema(nullable = true, example = 42)]
pub seed: Option<u64>,
}

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@ -23,6 +23,8 @@ use tracing_subscriber::{EnvFilter, Layer};
struct Args {
#[clap(default_value = "128", long, env)]
max_concurrent_requests: usize,
#[clap(default_value = "2", long, env)]
max_best_of: usize,
#[clap(default_value = "4", long, env)]
max_stop_sequences: usize,
#[clap(default_value = "1000", long, env)]
@ -55,6 +57,7 @@ fn main() -> Result<(), std::io::Error> {
// Pattern match configuration
let Args {
max_concurrent_requests,
max_best_of,
max_stop_sequences,
max_input_length,
max_total_tokens,
@ -145,6 +148,7 @@ fn main() -> Result<(), std::io::Error> {
server::run(
compat_return_full_text,
max_concurrent_requests,
max_best_of,
max_stop_sequences,
max_input_length,
max_total_tokens,

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@ -1,9 +1,10 @@
/// HTTP Server logic
use crate::infer::{InferError, InferStreamResponse};
use crate::infer::{InferError, InferResponse, InferStreamResponse};
use crate::validation::ValidationError;
use crate::{
CompatGenerateRequest, Details, ErrorResponse, FinishReason, GenerateParameters,
GenerateRequest, GenerateResponse, Infer, PrefillToken, StreamDetails, StreamResponse, Token,
Validation,
BestOfSequence, CompatGenerateRequest, Details, ErrorResponse, FinishReason,
GenerateParameters, GenerateRequest, GenerateResponse, Infer, PrefillToken, StreamDetails,
StreamResponse, Token, Validation,
};
use axum::extract::Extension;
use axum::http::{HeaderMap, Method, StatusCode};
@ -64,6 +65,7 @@ async fn health(infer: Extension<Infer>) -> Result<(), (StatusCode, Json<ErrorRe
.generate(GenerateRequest {
inputs: "liveness".to_string(),
parameters: GenerateParameters {
best_of: None,
temperature: None,
repetition_penalty: None,
top_k: None,
@ -128,17 +130,51 @@ async fn generate(
let details = req.0.parameters.details;
// Inference
let response = infer.generate(req.0).await?;
let (response, best_of_responses) = match req.0.parameters.best_of {
Some(best_of) if best_of > 1 => {
let (response, best_of_responses) = infer.generate_best_of(req.0, best_of).await?;
(response, Some(best_of_responses))
}
_ => (infer.generate(req.0).await?, None),
};
// Token details
let details = match details {
true => Some(Details {
true => {
// convert best_of_responses
let best_of_sequences = best_of_responses.map(|responses: Vec<InferResponse>| {
responses
.into_iter()
.map(|response: InferResponse| {
// Add prompt if return_full_text
let mut output_text = response.generated_text.text;
if let Some(prompt) = &add_prompt {
output_text = prompt.clone() + &output_text;
}
BestOfSequence {
generated_text: output_text,
finish_reason: FinishReason::from(
response.generated_text.finish_reason,
),
generated_tokens: response.generated_text.generated_tokens,
prefill: response.prefill,
tokens: response.tokens,
seed: response.generated_text.seed,
}
})
.collect()
});
Some(Details {
finish_reason: FinishReason::from(response.generated_text.finish_reason),
generated_tokens: response.generated_text.generated_tokens,
prefill: response.prefill,
tokens: response.tokens,
seed: response.generated_text.seed,
}),
best_of_sequences,
})
}
false => None,
};
@ -279,6 +315,8 @@ async fn generate_stream(
}
let details = req.0.parameters.details;
let best_of = req.0.parameters.best_of.unwrap_or(1);
if best_of == 1 {
match infer.generate_stream(req.0).instrument(info_span!(parent: &span, "async_stream")).await {
Ok(mut response_stream) => {
// Server-Sent Event stream
@ -383,6 +421,12 @@ async fn generate_stream(
tracing::error!("{err}");
yield Ok(Event::from(err));
}
} else {
let err = InferError::from(ValidationError::BestOfStream);
metrics::increment_counter!("tgi_request_failure", "err" => "validation");
tracing::error!("{err}");
yield Ok(Event::from(err));
}
};
(headers, Sse::new(stream).keep_alive(KeepAlive::default()))
@ -404,6 +448,7 @@ async fn metrics(prom_handle: Extension<PrometheusHandle>) -> String {
pub async fn run(
compat_return_full_text: bool,
max_concurrent_requests: usize,
max_best_of: usize,
max_stop_sequences: usize,
max_input_length: usize,
max_total_tokens: usize,
@ -430,6 +475,7 @@ pub async fn run(
PrefillToken,
Token,
GenerateResponse,
BestOfSequence,
Details,
FinishReason,
StreamResponse,
@ -454,6 +500,7 @@ pub async fn run(
let validation = Validation::new(
validation_workers,
tokenizer,
max_best_of,
max_stop_sequences,
max_input_length,
max_total_tokens,

View File

@ -1,4 +1,4 @@
use crate::validation::ValidationError::EmptyInput;
use crate::validation::ValidationError::{BestOfSampling, BestOfSeed, EmptyInput};
/// Payload validation logic
use crate::{GenerateParameters, GenerateRequest};
use rand::rngs::ThreadRng;
@ -13,6 +13,9 @@ use tracing::{instrument, Span};
/// Validation
#[derive(Debug, Clone)]
pub struct Validation {
/// maximum value for the best_of parameter
#[allow(dead_code)]
max_best_of: usize,
/// Channel to communicate with the background validation task
sender: mpsc::UnboundedSender<ValidationRequest>,
}
@ -21,6 +24,7 @@ impl Validation {
pub(crate) fn new(
workers: usize,
tokenizer: Tokenizer,
max_best_of: usize,
max_stop_sequences: usize,
max_input_length: usize,
max_total_tokens: usize,
@ -39,6 +43,7 @@ impl Validation {
));
Self {
max_best_of,
sender: validation_sender,
}
}
@ -60,6 +65,20 @@ impl Validation {
// Unwrap is safe here
receiver.await.unwrap()
}
/// Validate the best_of parameter
#[instrument(skip_all)]
pub(crate) fn validate_best_of(&self, best_of: usize) -> Result<usize, ValidationError> {
if self.max_best_of == 1 && best_of != 1 {
return Err(ValidationError::BestOfDisabled);
}
if best_of > self.max_best_of {
return Err(ValidationError::BestOf(self.max_best_of, best_of));
}
Ok(best_of)
}
}
/// Validation task
@ -150,6 +169,7 @@ fn validate(
rng: &mut ThreadRng,
) -> Result<ValidGenerateRequest, ValidationError> {
let GenerateParameters {
best_of,
temperature,
repetition_penalty,
top_k,
@ -164,6 +184,18 @@ fn validate(
..
} = request.parameters;
// sampling must be true when best_of > 1
let best_of = best_of.unwrap_or(1);
let sampling = do_sample
|| temperature.is_some()
|| top_k.is_some()
|| top_p.is_some()
|| typical_p.is_some();
if best_of > 1 && !sampling {
return Err(BestOfSampling);
}
let temperature = temperature.unwrap_or(1.0);
if temperature <= 0.0 {
return Err(ValidationError::Temperature);
@ -217,7 +249,12 @@ fn validate(
// If seed is None, assign a random one
let seed = match seed {
None => rng.gen(),
Some(seed) => seed,
Some(seed) => {
if best_of > 1 {
return Err(BestOfSeed);
}
seed
}
};
// Check if inputs is empty
@ -307,6 +344,16 @@ pub(crate) struct ValidGenerateRequest {
#[derive(Error, Debug)]
pub enum ValidationError {
#[error("`best_of` must be > 0 and <= {0}. Given: {1}")]
BestOf(usize, usize),
#[error("`best_of` != 1 is not allowed for this endpoint")]
BestOfDisabled,
#[error("you must use sampling when `best_of` is > 1")]
BestOfSampling,
#[error("`seed` must not be set when `best_of` > 1")]
BestOfSeed,
#[error("`best_of` != 1 is not supported when streaming tokens")]
BestOfStream,
#[error("`temperature` must be strictly positive")]
Temperature,
#[error("`repetition_penalty` must be strictly positive")]