Add severity-based and trace-based log record processors

specification/logs/sdk.md

@@ -36,6 +36,8 @@ weight: 3
   * [Built-in processors](#built-in-processors)
     + [Simple processor](#simple-processor)
     + [Batching processor](#batching-processor)
+    + [Severity based processor](#severity-based-processor)
+    + [Trace based processor](#trace-based-processor)
 - [LogRecordExporter](#logrecordexporter)
   * [LogRecordExporter operations](#logrecordexporter-operations)
     + [Export](#export)
@@ -456,6 +458,9 @@ make the flush timeout configurable.
 The standard OpenTelemetry SDK MUST implement both simple and batch processors,
 as described below.
 
+**Status**: [Development](../document-status.md) - The SDK SHOULD implement
+severity based and trace based processors, as described below.
+
 Other common processing scenarios SHOULD be first considered
 for implementation out-of-process
 in [OpenTelemetry Collector](../overview.md#collector).
@@ -495,6 +500,54 @@ to make sure that they are not invoked concurrently.
 * `maxExportBatchSize` - the maximum batch size of every export. It must be
   smaller or equal to `maxQueueSize`. The default value is `512`.
 
+#### Severity based processor
+
+**Status**: [Development](../document-status.md)
+
+This processor filters log records by minimum severity level.
+
+**Required operations:**
+
+* [`Enabled`](#enabled-1) - Return `false` if the provided
+  [Severity Number](./data-model.md#field-severitynumber) is below the
+  configured `minimumSeverity`. Otherwise, forward to the delegate's
+  `Enabled` method if available and return `true` if not available.
+* [`OnEmit`](#onemit) - If the log record's severity is below the configured
+  `minimumSeverity`, do not forward it to the delegate. Otherwise, forward the
+  log record to the delegate.
+* [`Shutdown`](#shutdown) - Forward to the delegate's `Shutdown` method.
+* [`ForceFlush`](#forceflush-1) - Forward to the delegate's `ForceFlush` method.
+
+**Configurable parameters:**
+
+* `minimumSeverity` - the minimum severity level required for passing the
+  log record on to the delegate.
+* `delegate` - the processor to delegate to for log records that are not
+  filtered out.
+
+#### Trace based processor
+
+**Status**: [Development](../document-status.md)
+
+This processor filters log records by span sampling status.
+
+**Required operations:**
+
+* [`Enabled`](#enabled-1) - Return `false` if the current
+  [Context](../context/README.md) contains a valid span context that is not
+  sampled. Otherwise, forward to the delegate's `Enabled` method if available
+  and return `true` if not available.
+* [`OnEmit`](#onemit) - If the log record is associated with a valid span
+  context that is not sampled, do not forward it to the delegate. Otherwise,
+  forward the log record to the delegate.
+* [`Shutdown`](#shutdown) - Forward to the delegate's `Shutdown` method.
+* [`ForceFlush`](#forceflush-1) - Forward to the delegate's `ForceFlush` method.
+
+**Configurable parameters:**
+
+* `delegate` - the processor to delegate to for log records that are not
+  filtered out.
+
 ## LogRecordExporter
 
 `LogRecordExporter` defines the interface that protocol-specific exporters must