In the tech industry, one day a skill is hot, the next it's not. IT professionals spend a lot of their career learning, training, and trying to keep up.
Job-hunting site Dice prides itself on helping IT pros navigate which skills to pursue. It just concluded an analysis of its database of 80,000-plus tech jobs from April 2015 through April 2016 to determine the fastest-growing skills based on job openings.
We then crosschecked those skills against Dice's annual-salary survey, published in February, which offered the average salary for jobs using those particular skills in 2015.
The good news? All of them are part of jobs that command average salaries of over $110,000.
No. 8: Cassandra, job openings up 32 percent, worth $147,811
Cassandra is a special kind of database called a NoSQL, which is part of the big-data trend. NoSQL databases can handle massive amounts of data, spread across cheaper, low-end servers.
Cassandra was born at Facebook, but the company released it as a free and open-source project, and today it is used at companies including Apple, Comcast, Instagram, Spotify, eBay, Rackspace, and Netflix.
No. 7: Hive, up 32 percent, worth $129,400
Hive is another skill in high demand as part of the big-data phenomenon, particularly a big-data tech called Hadoop.
Hadoop is software to store all kinds of data across many low-cost computer servers. Hive provides a way to extract information from Hadoop using the same kind of traditional methods used by regular databases.
In geek speak: it gives Hadoop a database-query interface.
No. 6: Cloud computing, up 33 percent, worth $112,972
Enterprises are increasingly using shared, rented computer servers, software, and storage accessed over the internet from companies like Amazon, Microsoft, and Google.
That's a concept called cloud computing, named because, once upon a time, diagram-drawing tools used a picture of a "cloud" as the icon to represent the internet.
People who have skills working with cloud computing are in high demand these days.
No. 5: JIRA, up 37 percent, worth $111,103
The new JIRA software, tailored for programming teams.
Atlassian's JIRA began life as a bug-tracking tool for programmers, but has since grown into project-management software for IT people and others used by over 35,000 companies.
No. 4: Big data, up 43 percent, worth $121,328
Big data is the catchall phrase for a long list of technologies that allow companies to affordably store massive amounts of information from all sorts of sources. Companies can then sift through it all to find insights.
Companies are looking for expertise in setting up these systems, managing them, running them, analyzing the data, and choosing which tech to deploy for which big-data project.
No. 3: Salesforce, up 48 percent, worth $107,810
Salesforce is a cloud-software company best known for its "customer relationship management" (CRM) software. This software lets a company keep track of customers, prospects, and all sorts of interactions.
But Salesforce has now become a giant ecosystem of other add-on software products that work with CRM, each of which requires special skills in working with and managing Salesforce systems.
No. 2: Azure, up 95 percent, worth $110,707
Azure is the name for Microsoft's cloud-computing service. Most big companies use Microsoft's software, and the company has made it really easy for these customers to use its cloud for everything from securing their mobile devices to hosting their apps.
Consequently, IT professionals who know how to use Azure are increasingly in demand.
Microsoft has bet its future on being a kingpin of the cloud-computing market, so this is a good sign for Microsoft.
No. 1: Spark, up 120 percent, worth $113,214
Spark is another big-data technology associated with Hadoop, a newer way to sift through the data to find answers. Its claim to fame is that it crunches through the information faster than the traditional method, known as MapReduce.
In 2015, IBM announced that it was investing $300 million to help develop this free and open-source technology, calling it "the most significant open-source project of the next decade."
Spark's creator, Matei Zaharia, has co-founded a hot startup called Databricks, which provides a commercial version of Spark.