Cassandra DAO: Safety trigger to fall back to use_ts_key_value_partitioning_on_read as true if estimated partitions count is greater than safety trigger value.

application/src/main/resources/thingsboard.yml

@@ -303,8 +303,11 @@ cassandra:
     default_fetch_size: "${CASSANDRA_DEFAULT_FETCH_SIZE:2000}"
     # Specify partitioning size for timestamp key-value storage. Example: MINUTES, HOURS, DAYS, MONTHS, INDEFINITE
     ts_key_value_partitioning: "${TS_KV_PARTITIONING:MONTHS}"
-    # Enable/Disable timestamp key-value partioning on read queries
+    # Enable/Disable timestamp key-value partitioning on read queries
     use_ts_key_value_partitioning_on_read: "${USE_TS_KV_PARTITIONING_ON_READ:true}"
+    # Safety trigger to fall back to use_ts_key_value_partitioning_on_read as true if estimated partitions count is greater than safety trigger value.
+    # It helps to prevent building huge partition list (OOM) for corner cases (like from 0 to infinity) and prefer fewer reads strategy from NoSQL database
+    use_ts_key_value_partitioning_on_read_max_estimated_partition_count: "${USE_TS_KV_PARTITIONING_ON_READ_MAX_ESTIMATED_PARTITION_COUNT:40}"
     # The number of partitions that are cached in memory of each service. It is useful to decrease the load of re-inserting the same partitions again
     ts_key_value_partitions_max_cache_size: "${TS_KV_PARTITIONS_MAX_CACHE_SIZE:100000}"
     # Timeseries Time To Live (in seconds) for Cassandra Record. 0 - record has never expired

dao/src/main/java/org/thingsboard/server/dao/timeseries/CassandraBaseTimeseriesDao.java

@@ -113,6 +113,10 @@ public class CassandraBaseTimeseriesDao extends AbstractCassandraBaseTimeseriesD
     @Value("${cassandra.query.use_ts_key_value_partitioning_on_read:true}")
     private boolean useTsKeyValuePartitioningOnRead;
 
+    @Getter
+    @Value("${cassandra.query.use_ts_key_value_partitioning_on_read_max_estimated_partition_count:40}") // 3+ years for MONTHS
+    private int useTsKeyValuePartitioningOnReadMaxEstimatedPartitionCount;
+
     @Value("${cassandra.query.ts_key_value_partitions_max_cache_size:100000}")
     private long partitionsCacheSize;
 
@@ -415,22 +419,41 @@ public class CassandraBaseTimeseriesDao extends AbstractCassandraBaseTimeseriesD
                         readResultsProcessingExecutor);
     }
 
-    private ListenableFuture<List<Long>> getPartitionsFuture(TenantId tenantId, TsKvQuery query, EntityId entityId, long minPartition, long maxPartition) {
+    ListenableFuture<List<Long>> getPartitionsFuture(TenantId tenantId, TsKvQuery query, EntityId entityId, long minPartition, long maxPartition) {
         if (isFixedPartitioning()) { //no need to fetch partitions from DB
             return Futures.immediateFuture(FIXED_PARTITION);
         }
         if (!isUseTsKeyValuePartitioningOnRead()) {
-            return Futures.immediateFuture(calculatePartitions(minPartition, maxPartition));
+            final long estimatedPartitionCount = estimatePartitionCount(minPartition, maxPartition);
+            if  (estimatedPartitionCount <= useTsKeyValuePartitioningOnReadMaxEstimatedPartitionCount) {
+                return Futures.immediateFuture(calculatePartitions(minPartition, maxPartition, (int) estimatedPartitionCount));
+            }
         }
+        return getPartitionsFromDB(tenantId, query, entityId, minPartition, maxPartition);
+    }
+
+    ListenableFuture<List<Long>> getPartitionsFromDB(TenantId tenantId, TsKvQuery query, EntityId entityId, long minPartition, long maxPartition) {
         TbResultSetFuture partitionsFuture = fetchPartitions(tenantId, entityId, query.getKey(), minPartition, maxPartition);
         return Futures.transformAsync(partitionsFuture, getPartitionsArrayFunction(), readResultsProcessingExecutor);
     }
 
+    // Optimistic estimation of partition count, expected to be never called for infinite partitioning
+    long estimatePartitionCount(long minPartition, long maxPartition) {
+        if (maxPartition > minPartition) {
+            return (maxPartition - minPartition) / tsFormat.getDurationMs() + 2; //at least 2 partitions, at max 2 partitions overestimated
+        }
+        return 1; // 1 or 0, but 1 is more optimistic
+    }
+
     List<Long> calculatePartitions(long minPartition, long maxPartition) {
+       return calculatePartitions(minPartition, maxPartition, 0);
+    }
+
+    List<Long> calculatePartitions(long minPartition, long maxPartition, int estimatedPartitionCount) {
         if (minPartition == maxPartition) {
             return Collections.singletonList(minPartition);
         }
-        List<Long> partitions = new ArrayList<>();
+        List<Long> partitions = estimatedPartitionCount > 0 ? new ArrayList<>(estimatedPartitionCount) : new ArrayList<>();
 
         long currentPartition = minPartition;
         LocalDateTime currentPartitionTime = LocalDateTime.ofInstant(Instant.ofEpochMilli(currentPartition), ZoneOffset.UTC);

dao/src/main/java/org/thingsboard/server/dao/timeseries/NoSqlTsPartitionDate.java

@@ -15,32 +15,29 @@
  */
 package org.thingsboard.server.dao.timeseries;
 
+import lombok.Getter;
+
 import java.time.LocalDateTime;
 import java.time.ZoneOffset;
 import java.time.temporal.ChronoUnit;
 import java.time.temporal.TemporalUnit;
 import java.util.Optional;
+import java.util.concurrent.TimeUnit;
 
+@Getter
 public enum NoSqlTsPartitionDate {
 
     MINUTES("yyyy-MM-dd-HH-mm", ChronoUnit.MINUTES), HOURS("yyyy-MM-dd-HH", ChronoUnit.HOURS), DAYS("yyyy-MM-dd", ChronoUnit.DAYS), MONTHS("yyyy-MM", ChronoUnit.MONTHS), YEARS("yyyy", ChronoUnit.YEARS),INDEFINITE("",ChronoUnit.FOREVER);
 
     private final String pattern;
     private final transient TemporalUnit truncateUnit;
+    private final transient long durationMs;
     public final static LocalDateTime EPOCH_START = LocalDateTime.ofEpochSecond(0,0, ZoneOffset.UTC);
 
     NoSqlTsPartitionDate(String pattern, TemporalUnit truncateUnit) {
         this.pattern = pattern;
         this.truncateUnit = truncateUnit;
-    }
-
-
-    public String getPattern() {
-        return pattern;
-    }
-
-    public TemporalUnit getTruncateUnit() {
-        return truncateUnit;
+        this.durationMs = TimeUnit.SECONDS.toMillis(this.truncateUnit.getDuration().getSeconds());
     }
 
     public LocalDateTime truncatedTo(LocalDateTime time) {

dao/src/test/java/org/thingsboard/server/dao/timeseries/CassandraBaseTimeseriesDaoPartitioningMinutesAlwaysExistsTest.java

@@ -117,4 +117,16 @@ public class CassandraBaseTimeseriesDaoPartitioningMinutesAlwaysExistsTest {
                 ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2022-10-10T00:10:00Z").getTime()));
     }
 
+    @Test
+    public void testEstimatePartitionCount() throws ParseException {
+        assertThat(tsDao.estimatePartitionCount(0, Long.MAX_VALUE)).as("centuries").isEqualTo(153_722_867_280_914L);
+        assertThat(tsDao.estimatePartitionCount(0, 0)).as("single").isEqualTo(1L);
+        long startTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2019-12-12T00:00:00Z").getTime());
+        long endTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2021-01-31T23:59:59Z").getTime());
+        assertThat(tsDao.estimatePartitionCount(startTs, endTs)).as("600,479 minutes + 2 spare periods").isEqualTo(600479 + 2);
+        assertThat(tsDao.estimatePartitionCount(endTs, startTs)).as("wrong period estimated as 1").isEqualTo(1L);
+    }
+
 }

dao/src/test/java/org/thingsboard/server/dao/timeseries/CassandraBaseTimeseriesDaoPartitioningMonthsAlwaysExistsTest.java

@@ -15,25 +15,35 @@
  */
 package org.thingsboard.server.dao.timeseries;
 
+import com.google.common.util.concurrent.ListenableFuture;
 import lombok.extern.slf4j.Slf4j;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Answers;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.mock.mockito.MockBean;
 import org.springframework.test.context.TestPropertySource;
+import org.springframework.test.context.bean.override.mockito.MockitoSpyBean;
 import org.springframework.test.context.junit4.SpringRunner;
+import org.thingsboard.server.common.data.id.TenantId;
+import org.thingsboard.server.common.data.kv.TsKvQuery;
 import org.thingsboard.server.dao.cassandra.CassandraCluster;
 import org.thingsboard.server.dao.nosql.CassandraBufferedRateReadExecutor;
 import org.thingsboard.server.dao.nosql.CassandraBufferedRateWriteExecutor;
 
 import java.text.ParseException;
 import java.util.List;
+import java.util.UUID;
 
 import static org.apache.commons.lang3.time.DateFormatUtils.ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.BDDMockito.willReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
 
 @RunWith(SpringRunner.class)
 @SpringBootTest(classes = CassandraBaseTimeseriesDao.class)
@@ -50,7 +60,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 @Slf4j
 public class CassandraBaseTimeseriesDaoPartitioningMonthsAlwaysExistsTest {
 
-    @Autowired
+    @MockitoSpyBean
     CassandraBaseTimeseriesDao tsDao;
 
     @MockBean(answer = Answers.RETURNS_MOCKS)
@@ -131,4 +141,53 @@ public class CassandraBaseTimeseriesDaoPartitioningMonthsAlwaysExistsTest {
                 ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2021-01-01T00:00:00Z").getTime()));
     }
 
+    @Test
+    public void testEstimatePartitionCount() throws ParseException {
+        assertThat(tsDao.estimatePartitionCount(0, Long.MAX_VALUE)).as("centuries").isEqualTo(3_507_324_297L);
+        assertThat(tsDao.estimatePartitionCount(0, 0)).as("single").isEqualTo(1L);
+        long startTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2019-12-12T00:00:00Z").getTime());
+        long endTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2021-01-31T23:59:59Z").getTime());
+        assertThat(tsDao.estimatePartitionCount(startTs, endTs)).as("13 month + 2 spare periods").isEqualTo(13 + 2);
+        assertThat(tsDao.estimatePartitionCount(endTs, startTs)).as("wrong period estimated as 1").isEqualTo(1L);
+    }
+
+    @Test
+    public void testGetPartitionsFutureModeratePartitionsCount() throws ParseException {
+        TenantId tenantId = TenantId.fromUUID(UUID.randomUUID());
+        TsKvQuery query = mock(TsKvQuery.class);
+        long startTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2019-12-12T00:00:00Z").getTime());
+        long endTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2021-01-31T23:59:59Z").getTime());
+
+        willReturn(mock(ListenableFuture.class)).given(tsDao).getPartitionsFromDB(tenantId, query, tenantId, startTs, endTs);
+
+        tsDao.getPartitionsFuture(tenantId, query, tenantId, startTs, endTs);
+
+        verify(tsDao).estimatePartitionCount(startTs, endTs);
+        verify(tsDao).calculatePartitions(eq(startTs), eq(endTs), anyInt());
+        verify(tsDao, never()).getPartitionsFromDB(tenantId, query, tenantId, startTs, endTs);
+    }
+
+    @Test
+    public void testGetPartitionsFutureHugePartitionsCountPreventOOMFallbackToDB() throws ParseException {
+
+        TenantId tenantId = TenantId.fromUUID(UUID.randomUUID());
+        TsKvQuery query = mock(TsKvQuery.class);
+        long startTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2000-12-12T00:00:00Z").getTime());
+        long endTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("3000-01-31T23:59:59Z").getTime());
+
+        willReturn(mock(ListenableFuture.class)).given(tsDao).getPartitionsFromDB(tenantId, query, tenantId, startTs, endTs);
+
+        tsDao.getPartitionsFuture(tenantId, query, tenantId, startTs, endTs);
+
+        verify(tsDao).estimatePartitionCount(startTs, endTs);
+        verify(tsDao, never()).calculatePartitions(eq(startTs), eq(endTs), anyInt());
+        verify(tsDao).getPartitionsFromDB(tenantId, query, tenantId, startTs, endTs);
+    }
+
 }

dao/src/test/java/org/thingsboard/server/dao/timeseries/CassandraBaseTimeseriesDaoPartitioningYearsAlwaysExistsTest.java

@@ -112,4 +112,16 @@ public class CassandraBaseTimeseriesDaoPartitioningYearsAlwaysExistsTest {
                 ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2025-01-01T00:00:00Z").getTime()));
     }
 
+    @Test
+    public void testEstimatePartitionCount() throws ParseException {
+        assertThat(tsDao.estimatePartitionCount(0, Long.MAX_VALUE)).as("centuries").isEqualTo(292_277_026L);
+        assertThat(tsDao.estimatePartitionCount(0, 0)).as("single").isEqualTo(1L);
+        long startTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2019-12-12T00:00:00Z").getTime());
+        long endTs = tsDao.toPartitionTs(
+                ISO_8601_EXTENDED_DATETIME_TIME_ZONE_FORMAT.parse("2021-01-31T23:59:59Z").getTime());
+        assertThat(tsDao.estimatePartitionCount(startTs, endTs)).as("2 years + 2 spare periods").isEqualTo(2 + 2);
+        assertThat(tsDao.estimatePartitionCount(endTs, startTs)).as("wrong period estimated as 1").isEqualTo(1L);
+    }
+
 }

dao/src/test/java/org/thingsboard/server/dao/timeseries/NoSqlTsPartitionDateTest.java

@@ -0,0 +1,41 @@
+/**
+ * Copyright © 2016-2025 The Thingsboard Authors
+ *
+ * Licensed 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 org.thingsboard.server.dao.timeseries;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class NoSqlTsPartitionDateTest {
+
+    @ParameterizedTest
+    @EnumSource(NoSqlTsPartitionDate.class)
+    void getDurationMsTest(NoSqlTsPartitionDate tsPartitionDate) throws Exception {
+        final Long durationMs = switch (tsPartitionDate) {
+            case MINUTES -> 60000L;
+            case HOURS -> 3600000L;
+            case DAYS -> 86400000L;
+            case MONTHS -> 2629746000L;
+            case YEARS -> 31556952000L;
+            case INDEFINITE -> Long.MAX_VALUE;
+            default -> null; //should be here in case a new enum value will be added in future
+        };
+        assertThat(durationMs).isNotNull();
+        assertThat(tsPartitionDate.getDurationMs()).isEqualTo(durationMs);
+    }
+
+}