Go GC: Latency Problem Solved Rick Hudson Google Engineer GopherCon Denver July 8, 2015 Google Confidential and Proprietary My Codefendants: The Cambridge Runtime Gang https://upload.wikimedia.o Software++ Hardware++ Hardware++ HW++ HW++ Software++ Software++ Software++ #1 Barrier: GC Latency Google Confidential and Proprietary When is the best time to do a GC? When nobody is looking. Google Confidential and Proprietary Or Trade Throughput for Reduced GC Latency Google Confidential and Proprietary Latency Nanosecond 1: Grace Hopper Nanosecond 11.8 inches Microsecond 5

Michael A Maniscalco ○ Software Architect and Principal Developer at Lime Trading ○ We develop low latency market data and trading software for use in HFT ● Personal ○ github.com/buildingcpp ■ Work Contracts

A single Celery process can process millions of tasks a minute, with sub- millisecond round-trip latency (using RabbitMQ, librabbitmq, and optimized settings). Flexible Almost every part of Celery can x(): ... By default, this exponential backoff will also introduce random jitter [https://en.wikipedia.org/wiki/Jitter] to avoid having all the tasks run at the same moment. It will also cap the maximum version 4.4. You can also set autoretry_for, retry_kwargs, retry_backoff, retry_backoff_max and retry_jitter options in class-based tasks: class BaseTaskWithRetry(Task): autoretry_for = (TypeError,)

A single Celery process can process millions of tasks a minute, with sub- millisecond round-trip latency (using RabbitMQ, librabbitmq, and optimized settings). Flexible Almost every part of Celery can x(): ... By default, this exponential backoff will also introduce random jitter [https://en.wikipedia.org/wiki/Jitter] to avoid having all the tasks run at the same moment. It will also cap the maximum version 4.4. You can also set autoretry_for, retry_kwargs, retry_backoff, retry_backoff_max and retry_jitter options in class-based tasks: class BaseTaskWithRetry(Task): autoretry_for = (TypeError,)

A single Celery process can process millions of tasks a minute, with sub- millisecond round-trip latency (using RabbitMQ, librabbitmq, and optimized settings). Flexible Almost every part of Celery can x(): ... By default, this exponential backoff will also introduce random jitter [https://en.wikipedia.org/wiki/Jitter] to avoid having all the tasks run at the same moment. It will also cap the maximum version 4.4. You can also set autoretry_for, retry_kwargs, retry_backoff, retry_backoff_max and retry_jitter options in class-based tasks: class BaseTaskWithRetry(Task): autoretry_for = (TypeError,)

A single Celery process can process millions of tasks a minute, with sub- millisecond round-trip latency (using RabbitMQ, librabbitmq, and optimized settings). Flexible Almost every part of Celery can x(): ... By default, this exponential backoff will also introduce random jitter [https://en.wikipedia.org/wiki/Jitter] to avoid having all the tasks run at the same moment. It will also cap the maximum version 4.4. You can also set autoretry_for, retry_kwargs, retry_backoff, retry_backoff_max and retry_jitter options in class-based tasks: class BaseTaskWithRetry(Task): autoretry_for = (TypeError,)

A single Celery process can process millions of tasks a minute, with sub- millisecond round-trip latency (using RabbitMQ, librabbitmq, and optimized settings). Flexible Almost every part of Celery can x(): ... By default, this exponential backoff will also introduce random jitter [https://en.wikipedia.org/wiki/Jitter] to avoid having all the tasks run at the same moment. It will also cap the maximum version 4.4. You can also set autoretry_for, retry_kwargs, retry_backoff, retry_backoff_max and retry_jitter options in class-based tasks: class BaseTaskWithRetry(Task): autoretry_for = (TypeError,)

A single Celery process can process millions of tasks a minute, with sub- millisecond round-trip latency (using RabbitMQ, librabbitmq, and optimized settings). Flexible Almost every part of Celery can x(): ... By default, this exponential backoff will also introduce random jitter [https://en.wikipedia.org/wiki/Jitter] to avoid having all the tasks run at the same moment. It will also cap the maximum version 4.4. You can also set autoretry_for, retry_kwargs, retry_backoff, retry_backoff_max and retry_jitter options in class-based tasks: class BaseTaskWithRetry(Task): autoretry_for = (TypeError,)

A single Celery process can process millions of tasks a minute, with sub- millisecond round-trip latency (using RabbitMQ, librabbitmq, and optimized settings). Flexible Almost every part of Celery can x(): ... By default, this exponential backoff will also introduce random jitter [https://en.wikipedia.org/wiki/Jitter] to avoid having all the tasks run at the same moment. It will also cap the maximum version 4.4. You can also set autoretry_for, retry_kwargs, retry_backoff, retry_backoff_max and retry_jitter options in class-based tasks: class BaseTaskWithRetry(Task): autoretry_for = (TypeError,)