Database

Problem: The client wanted to understand the logic behind the creation of SSTable (sorted string table) folders in Cassandra when data is written to a database table within a keyspace. Specifically, the question was about why each table has two directories in certain scenarios and how this logic affects the ability to achieve data backups […]

Problem: During a diagnostic call, it was observed that nodetool compactionstats was displaying 3,493 pending tasks related to the skyrt_prod1.event_state table. Despite new tasks being initiated and processed, these existing pending tasks remained uncleared, with no tasks currently in progress. This issue raised concerns about potential underlying problems with Cassandra’s compaction process. Solution: The accumulation […]

Problem: The client reported that data storage space was being exhausted because the incremental backups were being saved in the same location as the data storage. This issue forced the client to delete incremental backups to free up space for new data. The client requested a consultation on how to configure incremental backups to be […]

Problem: The client requested to review cluster configuration and advise any changes to the configuration parameters to avoid any potential issues proactively. Additionally, the client requested advice on how to identify Cassandra database cluster’s workload. Process: 1) Data Collection: Gathered configuration files Collected the last 5,000 lines of the system log 2) Expert Review: Conducted […]

Problem: Not Showing Patroni Output in PG DR Database. The team faced an issue where the Patroni status was visible on the production (PROD) server but not on the disaster recovery (DR) server. The discrepancy hindered the ability to monitor the DR environment effectively. Process: Request Patroni Configuration and Logs: Obtain patroni.yml from both PROD […]

Problem The client was planning an upgrade of the MySQL database server from Red Hat Enterprise Linux (RHEL) 7.x to RHEL 8.x. The MySQL version currently running on the server was 14.14 (Distrib 5.7.34). The client needed to understand the compatibility of this MySQL version with RHEL 8.x and sought guidance on any additional steps […]

Problem: The client reported a recurring issue with the application, which consistently threw an error: org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend. He was uncertain about the root cause of this error and sought assistance to diagnose and resolve the issue. The client’s initial request was to understand what should be checked […]

Problem: The client, deploying a production Cassandra cluster on OpenShift, encountered persistent communication issues between two datacenters, each hosting three Cassandra nodes. Despite initial configuration and verification, nodes in Datacenter 1 (“RCKL”) and Datacenter 2 (“CLSP”) were unable to establish consistent communication. SSL handshake failures and inconsistent OpenSSL connectivity tests exacerbated the problem, indicating potential […]

Problem: The client had a 6-node multi-DC setup for Cassandra (3 nodes in PROD – East US2 and 3 nodes in DR – West US2) and needed to alter a keyspace. The keyspace was initially defined as follows: CREATE KEYSPACE bulk_api_management WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '3'} AND durable_writes = true; The client wanted […]