{"version":"2.1.277","anchor":"transport-allocator-adds-backpressure-and-refusal-callbacks","canonical_anchor":"transport-allocator-adds-backpressure-and-refusal-callbacks","heading":"Transport allocator adds backpressure and refusal callbacks","tier":"internal","area":"Elsewhere","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.277\/e\/transport-allocator-adds-backpressure-and-refusal-callbacks","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.277","markdown":"### Transport allocator adds backpressure and refusal callbacks\n\nThe data-transport layer gained backpressure detection and refusal callbacks instead of always resending\n\n**What**\n\nThe internal channel\/frame allocator that manages data transport (its allocate, transmit, and free operations) now supports:\n\n- an `onRefused` callback that can run per allocation\n\n- backpressure detection (`isBackedUp`) checked before resending data\n\n- tracking of orphaned sequences when an allocation is freed\n\n- a `resend` flag on transmit, instead of the previous model of always resending\n\n**Why**\n\nThis makes the underlying transport more resilient: it can now detect when it's sending faster than the other side can handle (backpressure) and react to refused sends, rather than blindly resending every time.\n\n- Area: Elsewhere\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 2\/5"}