diff --git a/api/src/main/java/com/ning/billing/config/UsageConfig.java b/api/src/main/java/com/ning/billing/config/UsageConfig.java
new file mode 100644
index 0000000..d4cf6bd
--- /dev/null
+++ b/api/src/main/java/com/ning/billing/config/UsageConfig.java
@@ -0,0 +1,118 @@
+/*
+ * Copyright 2010-2012 Ning, Inc.
+ *
+ * Ning licenses this file to you under the Apache License, version 2.0
+ * (the "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.ning.billing.config;
+
+import org.skife.config.Config;
+import org.skife.config.Default;
+import org.skife.config.Description;
+import org.skife.config.TimeSpan;
+
+public interface UsageConfig extends KillbillConfig {
+
+ @Config("killbill.usage.timelines.length")
+ @Description("How long to buffer data in memory before flushing it to the database")
+ @Default("60m")
+ TimeSpan getTimelineLength();
+
+ // This is used to predict the number of samples between two times. It might be
+ // better to store this information on a per event category basis.
+ @Config("killbill.usage.timelines.pollingInterval")
+ @Description("How long to between attribute polling. This constant should be replaced by a flexible mechanism")
+ @Default("30s")
+ TimeSpan getPollingInterval();
+
+ @Config("killbill.usage.timelines.performForegroundWrites")
+ @Description("If true, perform database writes in the foreground; if false, in the background")
+ @Default("false")
+ boolean getPerformForegroundWrites();
+
+ @Config("killbill.usage.timelines.backgroundWriteBatchSize")
+ @Description("The number of TimelineChunks that must accumulate before we perform background writes, unless the max delay has been exceeded")
+ @Default("1000")
+ int getBackgroundWriteBatchSize();
+
+ @Config("killbill.usage.timelines.backgroundWriteCheckInterval")
+ @Description("The time interval between checks to see if we should perform background writes")
+ @Default("1s")
+ TimeSpan getBackgroundWriteCheckInterval();
+
+ @Config("killbill.usage.timelines.backgroundWriteMaxDelay")
+ @Description("The maximum timespan after pending chunks are added before we perform background writes")
+ @Default("1m")
+ TimeSpan getBackgroundWriteMaxDelay();
+
+ @Config("killbill.usage.timelines.timelineAggregationEnabled")
+ @Description("If true, periodically perform timeline aggregation; if false, don't aggregate")
+ @Default("true")
+ boolean getTimelineAggregationEnabled();
+
+ @Config("killbill.usage.timelines.maxAggregationLevel")
+ @Description("Max aggregation level")
+ @Default("5")
+ int getMaxAggregationLevel();
+
+ @Config("killbill.usage.timelines.chunksToAggregate")
+ @Description("A string with a comma-separated set of integers, one for each aggregation level, giving the number of sequential TimelineChunks with that aggregation level we must find to perform aggregation")
+ // These values translate to 4 hours, 16 hours, 2.7 days, 10.7 days, 42.7 days,
+ @Default("4,4,4,4,4")
+ String getChunksToAggregate();
+
+ @Config("killbill.usage.timelines.aggregationInterval")
+ @Description("How often to check to see if there are timelines ready to be aggregated")
+ @Default("2h")
+ TimeSpan getAggregationInterval();
+
+ @Config("killbill.usage.timelines.aggregationBatchSize")
+ @Description("The number of chunks to fetch in each batch processed")
+ @Default("4000")
+ int getAggregationBatchSize();
+
+ @Config("killbill.usage.timelines.aggregationSleepBetweenBatches")
+ @Description("How long to sleep between aggregation batches")
+ @Default("50ms")
+ TimeSpan getAggregationSleepBetweenBatches();
+
+ @Config("killbill.usage.timelines.maxChunkIdsToInvalidateOrDelete")
+ @Description("If the number of queued chunkIds to invalidate or delete is greater than or equal to this count, perform aggregated timeline writes and delete or invalidate the chunks aggregated")
+ @Default("1000")
+ int getMaxChunkIdsToInvalidateOrDelete();
+
+ @Config("killbill.usage.timelines.deleteAggregatedChunks")
+ @Description("If true, blast the old TimelineChunk rows; if false, leave them in peace, since they won't be accessed")
+ @Default("true")
+ boolean getDeleteAggregatedChunks();
+
+ @Config("killbill.usage.timelines.shutdownSaveMode")
+ @Description("What to save on shut down; either all timelines (save_all_timelines) or just the accumulator start times (save_start_times)")
+ @Default("save_all_timelines")
+ String getShutdownSaveMode();
+
+ @Config("killbill.usage.timelines.segmentsSize")
+ @Description("Direct memory segments size in bytes to allocate when buffering incoming events")
+ @Default("1048576")
+ int getSegmentsSize();
+
+ @Config("killbill.usage.timelines.maxNbSegments")
+ @Description("Max number of direct memory segments to allocate. This times the number of segments indicates the max amount of data buffered before storing a copy to disk")
+ @Default("10")
+ int getMaxNbSegments();
+
+ @Config("killbill.usage.timelines.spoolDir")
+ @Description("Spool directory for in-memory data")
+ @Default("/var/tmp/killbill")
+ String getSpoolDir();
+}
