OpenTelemetry Collector 0.159.0 release notes

pkg/exporterhelper: Add the pkg.exporterhelper.queueBatchEnabled feature gate (#14038, #13582, #12022) When enabled, the batch settings returned by NewDefaultQueueConfig() have batch::enabled true. See migration RFC.

pkg/exporterhelper: Record otelcol_exporter_queue_batch_send_size and otelcol_exporter_queue_batch_send_size_bytes after batching, and add otelcol_exporter_enqueue_size and otelcol_exporter_enqueue_size_bytes for enqueue-time sizes. (#14674) Previously the batch send size histograms were recorded at enqueue time (Offer), so they measured incoming request sizes rather than the post-batching request handed to the downstream sender. Those histograms are now recorded in the obs report sender. The previous enqueue-time measurements are preserved under the new otelcol_exporter_enqueue_size and otelcol_exporter_enqueue_size_bytes metrics for queue sizing. Users with the exporter batcher enabled will observe different values for otelcol_exporter_queue_batch_send_size*. otelcol_exporter_queue_batch_send_size and otelcol_exporter_queue_batch_send_size_bytes are now only recorded when sending_queue::batch is configured; they will not appear at all for exporters that do not enable batching.
pkg/scraperhelper: Use {record} instead of {datapoint} as the unit of the log record and profile record scraper metrics (#15730) Affects otelcol_scraper_scraped_log_records, otelcol_scraper_errored_log_records, otelcol_scraper_scraped_profile_records and otelcol_scraper_errored_profile_records.

extension/zpages: Make confighttp.ServerConfig a named field of Config instead of an embedded one. (#15308)
pkg/confighttp: Make configauth.Config a named field of AuthConfig instead of an embedded one. (#15308)

pkg/config/configretry: Migrate BackOffConfig to schema-based configuration generated by mdatagen. (#15502)
pkg/config/configtls: Migrate TLS core types to schema-based configuration generated by mdatagen. (#15693)