Hello everyone, We are currently using Cassandra 4.1.3 in a two-data-center cluster. Recently, we observed cross-node latency spikes of 3-4 seconds in one of our data centers. Below are the relevant logs from all three nodes in this DC:
DEBUG [ScheduledTasks:1] 2024-10-20 02:46:43,164 MonitoringTask.java:174 - 413 operations were slow in the last 5001 msecs: <SELECT ItemDetails, ItemDocuments, ItemISQDetails, ItemMappings, LastModified, ItemImages, ItemTitles, ItemCategories, ItemRating, ApprovalStatus, LocalName, UserIdentifier, IsDisplayed, VariantOptions FROM product_data.item_table WHERE item_table_display_id = 2854462277448 LIMIT 5000 ALLOW FILTERING>, time 3400 msec - slow timeout 500 msec <SELECT AlternateMasterCategoryData, MasterCategoryData, MasterGroupData, MasterSubCategoryData, MasterParentCategoryData FROM product_data.taxonomy_table WHERE master_id = 6402 LIMIT 5000 ALLOW FILTERING>, time 2309 msec - slow timeout 500 msec/cross-node <SELECT ItemDetails, ItemDocuments, ItemISQDetails, ItemMappings, LastModified, ItemImages, ItemTitles, ItemCategories, ItemRating, ApprovalStatus, LocalName, UserIdentifier, IsDisplayed, VariantOptions FROM product_data.item_table WHERE item_table_display_id = 24279823548 LIMIT 5000 ALLOW FILTERING>, time 3287 msec - slow timeout 500 msec/cross-node <SELECT ItemDetails, ItemDocuments, ItemISQDetails, ItemMappings, LastModified, ItemImages, ItemTitles, ItemCategories, ItemRating, ApprovalStatus, LocalName, UserIdentifier, IsDisplayed, VariantOptions FROM product_data.item_table WHERE item_table_display_id = 2854486264330 LIMIT 5000 ALLOW FILTERING>, time 2878 msec - slow timeout 500 msec/cross-node <SELECT AlternateMasterCategoryData, MasterCategoryData, MasterGroupData, MasterSubCategoryData, MasterParentCategoryData FROM product_data.taxonomy_table WHERE master_id = 27245 LIMIT 5000 ALLOW FILTERING>, time 3056 msec - slow timeout 500 msec/cross-node <SELECT AlternateMasterCategoryData, MasterCategoryData, MasterGroupData, MasterSubCategoryData, MasterParentCategoryData FROM product_data.taxonomy_table WHERE master_id = 32856 LIMIT 5000 ALLOW FILTERING>, time 2353 msec - slow timeout 500 msec/cross-node <SELECT AlternateMasterCategoryData, MasterCategoryData, MasterGroupData, MasterSubCategoryData, MasterParentCategoryData FROM product_data.taxonomy_table WHERE master_id = 95589 LIMIT 5000 ALLOW FILTERING>, time 2224 msec - slow timeout 500 msec/cross-node <SELECT ItemDetails, ItemDocuments, ItemISQDetails, ItemMappings, LastModified, ItemImages, ItemTitles, ItemCategories, ItemRating, ApprovalStatus, LocalName, UserIdentifier, IsDisplayed, VariantOptions FROM product_data.item_table WHERE item_table_display_id = 2854514159012 LIMIT 5000 ALLOW FILTERING>, time 3396 msec - slow timeout 500 msec Upon investigation, we found no GC pauses at the time of the latency, and CPU and memory utilization across all nodes appeared normal. Additionally, latency metrics from Grafana also showed standard performance. Given these observations, we are trying to identify the potential causes of this latency. Any insights or suggestions from the community would be greatly appreciated! Thank you!
