Diagnosing Problems in Production involves first preparing monitoring tools like OpsCenter, server monitoring, application metrics, and log aggregation. Common issues include incorrect server times causing data inconsistencies, tombstone overhead slowing queries, not using the proper snitch, and version mismatches breaking functionality. Diagnostic tools like htop, iostat, vmstat, dstat, strace, jstack, nodetool, histograms, and query tracing help narrow down performance problems which could be due to compaction, garbage collection, or other bottlenecks.
Diagnosing Problems in Production - CassandraJon Haddad
This presentation covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Readers will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This presentation is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
An introduction to core concepts in Apache Cassandra. We cover the evolution of database architecture as you try to scale a relational database to solve big data problems, and explain how Cassandra handles these problems efficiently.
Cassandra @ Sony: The good, the bad, and the ugly part 2DataStax Academy
This talk covers scaling Cassandra to a fast growing user base. Alex and Isaias will cover new best practices and how to work with the strengths and weaknesses of Cassandra at large scale. They will discuss how to adapt to bottlenecks while providing a rich feature set to the playstation community.
Diagnosing Problems in Production - CassandraJon Haddad
This presentation covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Readers will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This presentation is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
An introduction to core concepts in Apache Cassandra. We cover the evolution of database architecture as you try to scale a relational database to solve big data problems, and explain how Cassandra handles these problems efficiently.
Cassandra @ Sony: The good, the bad, and the ugly part 2DataStax Academy
This talk covers scaling Cassandra to a fast growing user base. Alex and Isaias will cover new best practices and how to work with the strengths and weaknesses of Cassandra at large scale. They will discuss how to adapt to bottlenecks while providing a rich feature set to the playstation community.
Intro deck from Cassandra Day Atlanta. Covers the evolution of data storage and analysis, the architecture of Cassandra, the read & write path, and using Cassandra for analytics. By Jon Haddad & Luke Tillman
Cassandra Day Atlanta 2015: Diagnosing Problems in ProductionDataStax Academy
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This talk is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
Cassandra Summit 2014: Diagnosing Problems in ProductionDataStax Academy
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster.
Beginning Operations: 7 Deadly Sins for Apache Cassandra OpsDataStax Academy
The internal battle has been fought, and Cassandra is your group's NoSQL platform of choice! Hooray! But now what? This talk will introduce you to all the basic operations concepts you need to know to start your foray into the wonderful world of Cassandra off right. Or even if you have already started but are looking for a solid holistic overview... this is the talk for you!
Scylla Summit 2018: Consensus in Eventually Consistent DatabasesScyllaDB
Eventually consistent databases choose to remain available under failure, allowing for conflicting data to be stored in different replicas (later repaired by background processes). Weakening the consistency guarantees improves not only availability, but also performance, as the number of replicas involved in a given operation can be minimized. There are, however, use-cases that require the opposite trade-off. Indeed, Apache Cassandra and Scylla provide Lightweight Transactions (LWT), which allow single-key linearizable updates. The mechanism underlying LWT is asynchronous consensus. In this talk, we'll describe the characteristics and requirements of Scylla's consensus implementation, and how it enables strongly consistent updates. We will also cover how consensus can be applied to other aspects of the system, such as schema changes, node membership, and range movements, in order to improve their reliability and safety. We will thus show that an eventually consistent database can leverage consensus without compromising either availability or performance.
Webinar: Diagnosing Apache Cassandra Problems in ProductionDataStax Academy
This session covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Viewers will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster.
Webinar: Getting Started with Apache CassandraDataStax
Would you like to learn how to use Cassandra but don’t know where to begin? Want to get your feet wet but you’re lost in the desert? Longing for a cluster when you don’t even know how to set up a node? Then look no further! Rebecca Mills, Junior Evangelist at Datastax, will guide you in the webinar “Getting Started with Apache Cassandra...”
You'll get an overview of Planet Cassandra’s resources to get you started quickly and easily. Rebecca will take you down the path that's right for you, whether you are a developer or administrator. Join if you are interested in getting Cassandra up and working in the way that suits you best.
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This talk is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
How to Monitor and Size Workloads on AWS i3 instancesScyllaDB
There is a new class of machines in town! Amazon recently unveiled i3, a new class of machines targeted at I/O-intensive workloads. Scylla will officially support i3, and previews are already available.
Join our webinar to learn how to build a state-of-the-art database solution. Presenters Glauber Costa and Eyal Gutkind will cover how to:
- Determine which workloads can benefit from i3 instances
- Ensure Scylla fully leverages the great resources in the i3 family
- Effectively navigate the Scylla monitoring system and identify bottlenecks
You'll also see a live demonstration with a dashboard featuring an i3 cluster with different data models and workloads.
Cassandra is pretty awesome, sure I am biased, but it rocks. Always on, tuneable consistency and multi-master architecture? Let’s get our web scale on and build a highly available app that never goes down!
Hold on a second. There is one key piece of the puzzle that has a massive impact on your applications availability: the client driver.
In this talk we will go through the how to best configure your clients to make the most of failure handling and tuneable consistency in Cassandra.
Scylla Summit 2016: Using ScyllaDB for a Microservice-based Pipeline in GoScyllaDB
How do you handle the continuous transformation and refinement of billions of entities with some sort of reliability and performance? In this talk, Henrik will describe how Scylla enabled him and his team to create a pipelined solution using a series of microservices written in Go communicating with each other using Nats. You’ll hear about the mistakes and learnings they had along the way as they built the services that led to the great performance and stability they are experiencing today.
Cassandra Day Chicago 2015: Diagnosing Problems in ProductionDataStax Academy
Speaker(s): Jon Haddad, Apache Cassandra Evangelist at DataStax
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This talk is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
Cassandra Day London 2015: Diagnosing Problems in ProductionDataStax Academy
Speaker(s): Jon Haddad, Apache Cassandra Evangelist at DataStax
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This talk is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
Webinar: Diagnosing Apache Cassandra Problems in ProductionDataStax Academy
This session covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Viewers will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster.
Diagnosing Problems in Production: Cassandra Summit 2014Jon Haddad
At the 2014 Cassandra summit we covered how to ensure that your production experience with Cassandra is top notch by identifying the proper tools that should be put in place beforehand, and what tools you need to identify problems in real time.
Presented by Jon Haddad & Blake Eggleston
Intro deck from Cassandra Day Atlanta. Covers the evolution of data storage and analysis, the architecture of Cassandra, the read & write path, and using Cassandra for analytics. By Jon Haddad & Luke Tillman
Cassandra Day Atlanta 2015: Diagnosing Problems in ProductionDataStax Academy
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This talk is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
Cassandra Summit 2014: Diagnosing Problems in ProductionDataStax Academy
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster.
Beginning Operations: 7 Deadly Sins for Apache Cassandra OpsDataStax Academy
The internal battle has been fought, and Cassandra is your group's NoSQL platform of choice! Hooray! But now what? This talk will introduce you to all the basic operations concepts you need to know to start your foray into the wonderful world of Cassandra off right. Or even if you have already started but are looking for a solid holistic overview... this is the talk for you!
Scylla Summit 2018: Consensus in Eventually Consistent DatabasesScyllaDB
Eventually consistent databases choose to remain available under failure, allowing for conflicting data to be stored in different replicas (later repaired by background processes). Weakening the consistency guarantees improves not only availability, but also performance, as the number of replicas involved in a given operation can be minimized. There are, however, use-cases that require the opposite trade-off. Indeed, Apache Cassandra and Scylla provide Lightweight Transactions (LWT), which allow single-key linearizable updates. The mechanism underlying LWT is asynchronous consensus. In this talk, we'll describe the characteristics and requirements of Scylla's consensus implementation, and how it enables strongly consistent updates. We will also cover how consensus can be applied to other aspects of the system, such as schema changes, node membership, and range movements, in order to improve their reliability and safety. We will thus show that an eventually consistent database can leverage consensus without compromising either availability or performance.
Webinar: Diagnosing Apache Cassandra Problems in ProductionDataStax Academy
This session covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Viewers will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster.
Webinar: Getting Started with Apache CassandraDataStax
Would you like to learn how to use Cassandra but don’t know where to begin? Want to get your feet wet but you’re lost in the desert? Longing for a cluster when you don’t even know how to set up a node? Then look no further! Rebecca Mills, Junior Evangelist at Datastax, will guide you in the webinar “Getting Started with Apache Cassandra...”
You'll get an overview of Planet Cassandra’s resources to get you started quickly and easily. Rebecca will take you down the path that's right for you, whether you are a developer or administrator. Join if you are interested in getting Cassandra up and working in the way that suits you best.
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This talk is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
How to Monitor and Size Workloads on AWS i3 instancesScyllaDB
There is a new class of machines in town! Amazon recently unveiled i3, a new class of machines targeted at I/O-intensive workloads. Scylla will officially support i3, and previews are already available.
Join our webinar to learn how to build a state-of-the-art database solution. Presenters Glauber Costa and Eyal Gutkind will cover how to:
- Determine which workloads can benefit from i3 instances
- Ensure Scylla fully leverages the great resources in the i3 family
- Effectively navigate the Scylla monitoring system and identify bottlenecks
You'll also see a live demonstration with a dashboard featuring an i3 cluster with different data models and workloads.
Cassandra is pretty awesome, sure I am biased, but it rocks. Always on, tuneable consistency and multi-master architecture? Let’s get our web scale on and build a highly available app that never goes down!
Hold on a second. There is one key piece of the puzzle that has a massive impact on your applications availability: the client driver.
In this talk we will go through the how to best configure your clients to make the most of failure handling and tuneable consistency in Cassandra.
Scylla Summit 2016: Using ScyllaDB for a Microservice-based Pipeline in GoScyllaDB
How do you handle the continuous transformation and refinement of billions of entities with some sort of reliability and performance? In this talk, Henrik will describe how Scylla enabled him and his team to create a pipelined solution using a series of microservices written in Go communicating with each other using Nats. You’ll hear about the mistakes and learnings they had along the way as they built the services that led to the great performance and stability they are experiencing today.
Cassandra Day Chicago 2015: Diagnosing Problems in ProductionDataStax Academy
Speaker(s): Jon Haddad, Apache Cassandra Evangelist at DataStax
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This talk is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
Cassandra Day London 2015: Diagnosing Problems in ProductionDataStax Academy
Speaker(s): Jon Haddad, Apache Cassandra Evangelist at DataStax
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster. This talk is intended for people with a general understanding of Cassandra, but it not required to have experience running it in production.
Webinar: Diagnosing Apache Cassandra Problems in ProductionDataStax Academy
This session covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Viewers will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster.
Diagnosing Problems in Production: Cassandra Summit 2014Jon Haddad
At the 2014 Cassandra summit we covered how to ensure that your production experience with Cassandra is top notch by identifying the proper tools that should be put in place beforehand, and what tools you need to identify problems in real time.
Presented by Jon Haddad & Blake Eggleston
Joel Jacobson (Datastax) - Diagnosing Cassandra Problems in ProductionOutlyer
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster.
Video: https://www.youtube.com/watch?v=9XrHoAxd0Is
Join DevOps Exchange London here: http://www.meetup.com/DevOps-Exchange-London
Follow DOXLON on twitter http://www.twitter.com/doxlon
Cassandra Summit 2014: Diagnosing Problems in ProductionDataStax Academy
Presenters: Jon Haddad
This sessions covers diagnosing and solving common problems encountered in production, using performance profiling tools. We’ll also give a crash course to basic JVM garbage collection tuning. Attendees will leave with a better understanding of what they should look for when they encounter problems with their in-production Cassandra cluster.
ApacheCon2010: Cache & Concurrency Considerations in Cassandra (& limits of JVM)srisatish ambati
Cache & Concurrency considerations for a high performance Cassandra deployment.
SriSatish Ambati
Cassandra has hit it's stride as a distributed java NoSQL database! It's fast, it's in-memory, it's scalable, it's seda; It's eventually consistent model makes it practical for the large & growing volumes of unstructured data usecases. It is also time to run it through the filters of performance analysis. For starters it runs on the java virtual machine and inherits the capabilities and culpabilities of the platform. This presentation reviews the runtime architecture, cache behavior & performance of a real-world workload on Cassandra. We blend existing system & jvm tools to get a quick overview & a breakdown of hotspots in the get, put & update operations. We highlight the role played by garbage collection & fragmentation due to long lived objects; We investigate lock contention in the data structures under concurrent usage. Cassandra uses UDP for management & TCP for data: we look at robustness of the communication patterns during high spikes and cluster-wide events. We review Non-Blocking Hashmap modifications to Cassandra that improve concurrency & amplify performance of this frontrunner in the NoSQL space
ApacheCon2010 NA
Wed, 03 November 2010 15:00
cassandra
Kubernetes at NU.nl (Kubernetes meetup 2019-09-05)Tibo Beijen
Slides of the presentation about Kubernetes practices and learnings at NU.nl.
This presentation was the first of two at the Dutch Kubernetes meetup at the Sanoma Netherlands offices, that took place on Sept. 5th 2019
Using Time Window Compaction Strategy For Time Series WorkloadsJeff Jirsa
Cassandra is a great fit for high write use cases, which makes it a popular choice for storing time series and sensor-collection workloads. At Crowdstrike, we've been using Cassandra for just that purpose, collecting petabytes of expiring time series data. In this talk, I'll discuss compaction in time series workloads, and the TimeWindowCompactionStrategy we developed specifically for this purpose. I'll detail TWCS specific configuration properties, some lesser known compaction sub-properties that apply to all compaction strategies, and also cover other general tricks and tuning that are useful for very large time-series workloads.
Development of concurrent services using In-Memory Data Gridsjlorenzocima
As part of OTN Tour 2014 believes this presentation which is intented for covers the basic explanation of a solution of IMDG, explains how it works and how it can be used within an architecture and shows some use cases. Enjoy
Similar to Diagnosing Problems in Production (Nov 2015) (20)
Cassandra Performance Tuning Like You've Been Doing It for Ten YearsJon Haddad
Slides from my performance talk at the 2023 Cassandra summit. Here I share my tools and process for improving Cassandra's performance. We look at the OODA loop, USE method, high level observability tools and system tools such as flame graphs and bcc-tools (ebpf). Using the example of giving more memory to Cassandra, we explore how to leverage async-profiler and bcc-tools to generate cpu flame graphs and histograms of I/O performance. We can see how identifying a performance bottleneck like time spent in decompression can guide us to solving the right problems - in this case resizing compression buffers.
Preview of Cassandra 2.2 and 3.0 features. Materialized views, user defined functions, user defined aggregations, new storage engine, rewritten hints, improved vnodes, native JSON support, updated garbage collector.
From the original abstract:
If you're already using Cassandra you're already aware of it’s strengths of high availability and linear scalability. The downside to this power is less query flexibility. For an OLTP system with an SLA this is an acceptable tradeoff, but for a data scientist it’s extremely limiting.
Enter Apache Spark. Apache spark complements an existing Cassandra cluster by providing a means of executing arbitrary queries, filters, sorting and aggregation. It’s possible to use functional constructs like map, filter, and reduce, as well as SQL and DataFrames.
In this presentation I’ll show you how to process Cassandra data in bulk or through a Kafka stream using Python. Then we’ll visualize our data using iPython notebooks, leveraging Pandas and matplotlib.
This is an advanced talk. We will assume existing knowledge of Cassandra and CQL.
These are the slides from my talk at Hulu in March 2015 discussing Apache Spark & Cassandra. I cover the evolution of data from a single machine to RDBMS (MySQL is the primary example) to big data systems.
On the Spark side, I covered batch jobs, streaming, Apache Kafka, an introduction to machine learning, clustering, logistic regression and recommendations systems (collaborative filtering).
The talk was recorded and is available on youtube: https://www.youtube.com/watch?v=_gFgU3phogQ
These slides are part of a presentation I gave on a Google Hangout on air regarding Python Performance Profiling. Specifically, I explore examining both development and production environments, build systems, testing frameworks (py.test & nose), various profilers for dev, and how to profile in production. The full talk is on youtube here: https://www.youtube.com/watch?v=tZc-v0-3OKQ
Python is a great programming language that works great with Cassandra. If your goal is to get your project into production quickly and iterate fast, Python is a great solution.
These slides are an introduction to the hands on portion from GitHub. https://github.com/rustyrazorblade/python-presentation
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
3. DataStax OpsCenter
• Will help with 90% of problems you
encounter
• Should be first place you look when
there's an issue
• Community version is free
• Enterprise version has additional
features
4. Server Monitoring & Alerts
• Monit
• monitor processes
• monitor disk usage
• send alerts
• Munin / collectd
• system perf statistics
• Nagios / Icinga
• Various 3rd party services
• Use whatever works for
you
6. Log Aggregation
• Hosted - Splunk, Loggly
• OSS - Logstash + Kibana, Greylog
• Many more…
• For best results all logs should be
aggregated here
• Oh yeah, and log your errors.
8. Incorrect Server Times
• Everything is written with a timestamp
• Last write wins
• Usually supplied by coordinator
• Can also be supplied by client
• What if your timestamps are wrong
because your clocks are off?
• Always install ntpd!
server
time: 10
server
time: 20
INSERT
real time: 12
DELETE
real time: 15
insert:20
delete:10
9. Tombstones
• Tombstones are a marker that data
no longer exists
• Tombstones have a timestamp just
like normal data
• They say "at time X, this no longer
exists"
10. Tombstone Hell
• Queries on partitions with a lot of tombstones require a lot of filtering
• This can be reaaaaaaally slow
• Consider:
• 100,000 rows in a partition
• 99,999 are tombstones
• How long to get a single row?
• Cassandra is not a queue!
read 99,999 tombstones
finally get the
right data
11. Not using a Snitch
• Snitch lets us distribute data in a fault tolerant way
• Changing this with a large cluster is time
consuming
• Dynamic Snitching
• use the fastest replica for reads
• RackInferring (uses IP to pick replicas)
• DC aware
• PropertyFileSnitch (cassandra-topology.properties)
• EC2Snitch & EC2MultiRegion
• GoogleCloudSnitch
• GossipingPropertyFileSnitch (recommended)
12. Version Mismatch
• SSTable format changed between
versions, making streaming
incompatible
• Version mismatch can break bootstrap,
repair, and decommission
• Introducing new nodes? Stick w/ the
same version
• Upgrade nodes in place
• One at a time
• One rack / AZ at a time (requires proper snitch)
13. Disk Space not Reclaimed
• When you add new nodes, data is
streamed from existing nodes
• … but it's not deleted from them after
• You need to run a nodetool cleanup
• Otherwise you'll run out of space just by
adding nodes
14. Using Shared Storage
• Single point of failure
• High latency
• Expensive
• Performance is about latency
• Can increase throughput with more
disks
• In general avoid EBS, SAN, NAS
15. Compaction
• Compaction merges SSTables
• Too much compaction?
• Opscenter provides insight into compaction
cluster wide
• nodetool
• compactionhistory
• getcompactionthroughput
• Leveled vs Size Tiered vs Date Tiered
• Leveled on SSD + Read Heavy
• Size tiered on Spinning rust
• Size tiered is great for write heavy time series workloads
• Date tiered is new and is showing HUGE promise
25. nodetool tpstats
• What's blocked?
• MemtableFlushWriter? - Slow
disks!
• also leads to GC issues
• Dropped mutations?
• need repair!
26. Histograms
• proxyhistograms
• High level read and write times
• Includes network latency
• cfhistograms <keyspace> <table>
• reports stats for single table on a single
node
• Used to identify tables with
performance problems
29. JVM GC Overview
• What is garbage collection?
• Manual vs automatic memory management
• Generational garbage collection (ParNew & CMS)
• New Generation
• Old Generation
30. New Generation
• New objects are created in the new gen (eden)
• Comprised of Eden & 2 survivor spaces (SurvivorRatio)
• Space identified by HEAP_NEWSIZE in cassandra-env.sh
• Historically limited to 800MB
31. Minor GC
• Occurs when Eden fills up
• Stop the world
• Dead objects are removed
• Copy current survivor to empty survivor
• Live objects are promoted into survivor (S0 & S1) then old gen
• Some survivor objects promoted to old gen (MaxTenuringThreshold)
• Spillover promoted to old gen
• Removing objects is fast, promoting objects is slow
32. Old Generation
• Objects are promoted to new gen from old gen
• Major GC
• Mostly concurrent
• 2 short stop the world pauses
33. Full GC
• Occurs when old gen fills up or
objects can’t be promoted
• Stop the world
• Collects all generations
• Defragments old gen
• These are bad!
• Massive pauses
34. Workload 1: Write Heavy
• Objects promoted: Memtables
• New gen too big
• Remember: promoting objects is slow!
• Huge new gen = potentially a lot of promotion
new gen old gen
too much promotion
35. Workload 2: Read Heavy
• Short lived objects being promoted into old gen
• Lots of minor GCs
• Read heavy workloads on SSD
• Results in frequent full GC
new gen old gen (full of short lived objects)
early promotion
fills up quickly
36. G1GC
• Improvement over ParNew+CMS
• Hard to tune
• CASSANDRA-8150
• G1 has more predictable pauses
• Better latency
• Many new gen, many old gen
• G1 is adaptive to usage
E SO
SO E
O S
EE
Eden Old GenS0 S1
37. GC Profiling
• Opscenter gc stats
• Look for correlations between gc spikes
and read/write latency
• Cassandra GC Logging
• Can be activated in cassandra-env.sh
• jstat
• prints gc activity
40. Narrow Down the Problem
• Is it even Cassandra? Check your
metrics!
• Nodes flapping / failing
• Check ops center
• Dig into system metrics
• Slow queries
• Find your bottleneck
• Check system stats
• JVM GC
• Compaction
• Histograms
• Tracing