Saving an Apache Spark DataFrame to a Vertica Table

Before you save an Apache Spark DataFrame to a Vertica table, make sure that you have the following setup: • Vertica cluster • Spark cluster • HDFS cluster. The Vertica Spark connector uses HDFS as an intermediate storage before it writes the DataFrame to Vertica. This checklist identifies potential problems you might encounter when using […]

Why is Vertica not Ingesting Data From Kafka?

Prerequisite: Verify that Vertica is up and running. If you want to troubleshoot why Vertica is not ingesting data from Kafka, follow this checklist. Step Task Results 1 Check whether Kafka is up and running. a. Examine the server log files for broker errors: $ BROKER_ROOT/logs/server.log If there are errors, consult the Kafka documentation. b. […]

Rebalance Taking a Long Time

After you add a node to your Vertica cluster or remove a node from your cluster, Vertica rebalances the data across all the nodes. If rebalancing is taking a long time, review these steps to find out the probable cause. Pre-Requisites To ensure a successful rebalance of your cluster, before you start the rebalance, take […]

Storage not Accessible and Vertica Fails to Start on Host

When the database host is still up and available and the power is on, Vertica storage may be inaccessible. Vertica may be down and the disk volumes /data and /catalog are unavailable. To troubleshoot, follow this checklist: Step Task Results 1 When the host rebooted, was there a problem auto-mounting the file systems? If yes, […]

Why is the Vertica Host Slow?

Symptoms: Sluggish response time Server is CPU-bound with a high load and too many processes. The host is possibly in a hung state, unable to make connections, or connections are hanging. Possible causes: Low available memory Too many concurrent active processes running Server actively using swap space To troubleshoot, follow this checklist: Step Task Results […]

What Should I do When Vertica Host is Down?

Each member of a Vertica cluster is referred to as a host throughout this checklist. The Vertica process communicates to other Vertica nodes in a cluster. Node refers to the Vertica database software. If your host is down, follow this checklist: Step Task Results 1 The Vertica host is physically powered off. No status lights […]

Debug Vertica Host Network Connectivity

If your host is physically available and the operating system is up and running, but you cannot access your network to the Vertica cluster, then external connections might not be possible. Client software connections are failing, and users are not able to ssh to the host. From observing a hardware console connection, it looks like […]

Upgrading Vertica

Vertica adds new features and enhances existing features with every release. To access the new and improved features, upgrade to the latest release of Vertica. Prerequisites Before you upgrade, perform the following: Perform a full database backup. If upgrade is unsuccessful, a full back up allows you to roll back to your current version. You […]

Expanding Your Cluster with New Nodes

Does your business need more storage? Consider adding nodes to your database if you need more storage. Vertica recommends that you add all new nodes at the same time. You can use this checklist to add nodes. These are basic steps. There are additional options discussed in the Vertica documentation. Step Task Results 1 Perform […]

What Should I do if the Ancient History Mark is not Advancing?

If the AHM is not advancing, troubleshoot using this checklist: Step Task Results 1 Check whether the Last Good Epoch (LGE) is advancing. => SELECT CURRENT_EPOCH, LAST_GOOD_EPOCH, AHM_EPOCH FROM SYSTEM; If the LGE is advancing, go to Step 2. If the LGE is not advancing, go to Step 5. 2 Check whether all nodes are […]

What Should I do to Shut Down Vertica Node for Maintenance?

If you need to shut down a Vertica node for maintenance, follow this checklist. Step Task Results 1 Verify that all cluster nodes are UP. $ /opt/vertica/bin/admintools -t view_cluster To avoid a long node recovery time after shutdown, if one or more nodes is DOWN, identify and restart them using the instructions in Restarting Vertica […]

What Should I do if my Node Recovery is Slow?

If you are running Vertica 7.2.x or later, perform recovery by table. For details, see Recovery By Table in the Vertica documentation. If you are running a Vertica version prior to 7.1.x, stop the ETL jobs and restart node recovery. Step Task Results 1 Monitor progress of recovery: => SELECT node_name, is_running FROM RECOVERY_STATUS; If […]

Why Does My Node Not Connect to Spread?

If your node is not connected to spread, follow the below steps to troubleshoot the connection issue. Step Task Results 1 Check whether the spread.conf file in the catalog folder is identical across all the nodes in the cluster. $ cat spread.conf If the spread.conf flies are identical across all nodes, go to Step 2. […]

Investigate Sudden Performance Degradation of a Query

Have you ever had a formerly fast-running query begin to run slowly? Use the following checklist to investigate the sudden slowdown of a formerly fast-running query. Step Task Results 1 Check for host error messages using the following commands: $ cat /var/log/messages $ dmesg If the cluster is in good health, go to Step 2. […]

What Should I do if the Database Performance is Slow?

Troubleshootusing the following checklist if your database performance is slow. Check if any of the following problems exist: Step Task Results 1 Is the query performance slow? If the query performance is slow, review the Query Performance checklist. If the query performance is not slow, go to Step 2. 2 Is the entire database slow? […]

Catalog Size Debugging

You have a large catalog if your catalog size is more than 10 GB or your catalog is changing more than 5% per day. This checklist gives you some suggestions and recommendations to monitor and reduce your database catalog size. The database catalog contains tractable metadata such as tables, projections, users, nodes, ROSes, and so […]

How Do I Manage Delete Vectors?

If you want to remove delete vectors manually or troubleshoot why they are not being removed automatically, follow this checklist. Step Task Results 1 Check if you have too many delete vectors (more than 100) in a projection. =>SELECT node_name, schema_name, projection_name, COUNT(*) num_dv, SUM(deleted_row_count) del_cnt, SUM(used_bytes) ubytes, MIN(start_epoch) min_epoch, MAX(start_epoch) max_epoch FROM delete_vectors GROUP […]

What Should I do When the Database Process is not Starting?

If you want to troubleshoot why the database process is not starting, follow this checklist. Step Task Results 1 Ensure Vertica is not already running on any node. $ ps –ef | grep vertica The Vertica process displays as follows: /opt/vertica/bin/vertica -D <catalog directory> -C <dbname> -n <node name> -h <host IP> -p <port> Prior […]

What Should I do When the Database Node is DOWN?

When database node is DOWN, troubleshoot using the following checklist. Step Task Results 1 Check whether your database is UP. $ admintools -t db_status -s UP If the database is UP, go to Step 2. If the database if not UP, restart your database. $ admintools -t start_db -d <Database_name> -p <Database_password> If the database […]