Was this page helpful?
Caution
You're viewing documentation for an unstable version of Scylla Rust Driver. Switch to the latest stable version.
Percentile speculative execution¶
This policy has access to Metrics shared with session, and triggers
speculative execution when the request to the current host is above a
given percentile.
This policy requires enabling crate feature "metrics" to be available.
Example¶
To use this policy in Session:
use std::{sync::Arc, time::Duration};
use scylla::client::session::Session;
use scylla::client::session_builder::SessionBuilder;
use scylla::{
policies::speculative_execution::PercentileSpeculativeExecutionPolicy,
client::execution_profile::ExecutionProfile,
};
let policy = PercentileSpeculativeExecutionPolicy {
max_retry_count: 3,
percentile: 99.0,
};
let handle = ExecutionProfile::builder()
.speculative_execution_policy(Some(Arc::new(policy)))
.build()
.into_handle();
let session: Session = SessionBuilder::new()
.known_node("127.0.0.1:9042")
.default_execution_profile_handle(handle)
.build()
.await?;