There are several ways to define a setting for a user in ClickHouse, depending on the use case and how long you want the setting to be configured. Let's look at a few scenarios...

Configure a setting for a single query​

A SELECT query can contain a SETTINGS clause where you can define any number of settings. The settings are only applied for that particular query. For example:

SELECT *
FROM my_table
SETTINGS max_threads = 8;

The maximum number of threads will be 8 for this particular query.

Configure a setting for a session​

You can define a setting for the lifetime of a client session using a SET clause. This is handy for ad-hoc testing or for when you want a setting to live for the lifetime of a few queries - but not longer.

SET max_threads = 8;

SELECT *
FROM my_table;

Configure a setting for a particular user​

Use ALTER USER to define a setting just for one user. For example:

ALTER USER my_user_name SETTINGS max_threads = 8;

You can verify it worked by logging out of your client, logging back in, then use the getSetting function:

SELECT getSetting('max_threads');

In order to execute the same query on all nodes of a ClickHouse Cloud service, we can use clusterAllReplicas.

For example, in order to get entries from a (node-local) system table from all nodes, you can use:

SELECT ... FROM clusterAllReplicas(default, system.TABLE) ...;

Similarly, you can execute the same SYSTEM statement on all nodes with a single statement, by using the ON CLUSTER clause:

SYSTEM ... ON CLUSTER default;

For example for dropping the filesystem cache from all nodes, you can use:

SYSTEM DROP FILESYSTEM CACHE ON CLUSTER default;

ClickHouse provides a simple and intuitive way to write filtered aggregates. For example, compare the standard SQL way to write filtered aggregates (which work fine in ClickHouse) with the shorthand syntax using the -If aggregate function combinator, which can be appended to any aggregate function:

--standard SQL
SELECT
   avg(number)
FILTER (WHERE number > 50)
FROM numbers(100)

--ClickHouse using an aggregate combinator
SELECT
   avgIf(number, number > 50)
FROM numbers(100)

Similarly, there is a -Distinct aggregate combinator:

--standard SQL
SELECT avg(DISTINCT number)

--ClickHouse using an aggregate combinator
SELECT avgDistinct(number)

Why are filtered aggregates are important? Because they allow you to implement the "segment comparison" feature in web analytics services. For example:

WITH
   Region = 'us' AS segment1,
   Browser = 'Chrome' AS segment2
SELECT
   uniqIf(UserID, segment1),
   uniqIf(UserID, segment2)
WHERE segment1 OR segment2

Check out the aggregate function combinator page in the docs for more details.

ClickHouse uses threads from the Global Thread pool to process queries and also perform background operations like merges and mutations. If there is no idle thread to process a query, then a new thread is created in the pool.

The maximum size of the global thread pool is determined by the max_thread_pool_size setting, which defaults to 10,000. You can modify this value in your config - here we set it to 20,000:

<max_thread_pool_size>20000</max_thread_pool_size>

If you modify max_thread_pool_size, we recommend changing thread_pool_queue_size to be the same value. The thread_pool_queue_size setting is the maximum number of jobs that can be scheduled on the Global Thread pool:

<thread_pool_queue_size>20000</thread_pool_queue_size>

You can also free up resources if your server has a lot of idle threads - using the max_thread_pool_free_size setting. The default is 1,000, which means your Global Thread pool will never have more than 1,000 idle threads. The following example increases the value to 2,000:

<max_thread_pool_free_size>2000</max_thread_pool_free_size>

Check out the docs for more details on the settings above and other settings that affect the Global Thread pool.

When a user-level setting is specified in the wrong place, the server won't start and an exception message is sent to the log. However, you can tell ClickHouse to ignore the incorrect setting using the skip_check_for_incorrect_settings setting:

Add the following to config.xml:

<skip_check_for_incorrect_settings>1</skip_check_for_incorrect_settings>

A client can view the server logs - even at a different level than what the server log level is configured to - by setting the send_logs_level client setting.

For example, suppose the client runs:

SET send_logs_level = 'trace';

The client will receive trace logs even if the server has log level set to info.

One useful scenario is to use send_logs_level to monitor the insertion of rows into a Distributed table:

• Enable logs in clickhouse-client using SET send_logs_level = 'trace';
• Run your INSERT query
• Inserts into a distributed table are asynchronous by default. The data is written into a local buffer on disk, then sent to remote servers in background.
• Logs will be sent from all nodes participating in the query processing (distributed tracing)

To check the status of distributed inserts, check the system.distribution_queue table. This table contains information about local files that are in the queue to be sent to the shards. These local files contain new parts that are created by inserting new data into the Distributed table in asynchronous mode.

To compare metrics between two queries, you must first obtain the query_id for both queries.

You can then run the following query:

WITH
    initial_query_id = '82142964-0b5d-4263-b996-302ce14bd779' AS second,
    initial_query_id = '7ea39e31-2f89-4085-843c-7246cb3baa5c' AS first
SELECT
    PE.1 AS metric,
    sumIf(PE.2, first) AS v1,
    sumIf(PE.2, second) AS v2,
    10 * log10(v2 / v1) AS dB
FROM clusterAllReplicas(
    default, system.query_log)
ARRAY JOIN ProfileEvents AS PE
WHERE (first OR second)
    AND (event_date >= today() - 3) AND (type = 2)
GROUP BY metric
HAVING v1 != v2
ORDER BY
    dB DESC,
    v2 DESC,
    metric ASC FORMAT PrettyCompactMonoBlock

You will receive a table with metrics comparing the two queries:

Query id: d7747d26-a231-47c8-ae8c-284895b1aeaf

┌─metric──────────────────────────────────────┬─────────v1─┬─────────v2─┬───────────────────────dB─┐
│ SystemTimeMicroseconds                      │   13812127 │   24081938 │       2.4143087099482767 │
│ SoftPageFaults                              │    2651887 │    4056889 │        1.846381108610876 │
│ DiskReadElapsedMicroseconds                 │    1113947 │    1273786 │        0.582319430863304 │
│ CachedReadBufferReadFromCacheMicroseconds   │    1126505 │    1285450 │         0.57322064922068 │
│ OSCPUVirtualTimeMicroseconds                │   70301588 │   80045377 │       0.5637111926869545 │
│ RealTimeMicroseconds                        │   86686457 │   96339471 │       0.4585300419916516 │
│ QueryProfilerRuns                           │        157 │        174 │       0.4464959587336597 │
│ NetworkSendBytes                            │     868197 │     940859 │        0.349062627796429 │
│ NetworkReceiveElapsedMicroseconds           │        161 │        174 │       0.3372337225075003 │
│ ArenaAllocBytes                             │ 1480589312 │ 1497366528 │      0.04893510724370622 │
│ OSWriteBytes                                │     380928 │     385024 │      0.04644905045763538 │
│ ArenaAllocChunks                            │       2153 │       2157 │      0.00806115279057892 │
│ FileOpen                                    │       7511 │       7516 │    0.0028900944828012766 │
│ OpenedFileCacheMisses                       │       7511 │       7516 │    0.0028900944828012766 │
│ ContextLock                                 │       5880 │       5881 │    0.0007385332589917156 │
│ OSReadChars                                 │ 2340791432 │ 2340789818 │ -0.000002994506583727971 │
│ OSWriteChars                                │    2521310 │    2513992 │    -0.012623549714419216 │
│ AggregationPreallocatedElementsInHashTables │  128039910 │  127563540 │    -0.016187974135432794 │
│ OSCPUWaitMicroseconds                       │    1543643 │    1536999 │    -0.018732829140838268 │
│ OpenedFileCacheHits                         │        539 │        534 │    -0.040475081581823065 │
│ UserTimeMicroseconds                        │   56490840 │   55961729 │     -0.04086908559606555 │
│ WaitMarksLoadMicroseconds                   │     388571 │     359985 │      -0.3318598023153847 │
│ ThreadpoolReaderTaskMicroseconds            │    3816669 │    3392522 │      -0.5116182478775457 │
│ NetworkSendElapsedMicroseconds              │       4745 │       4122 │      -0.6112822932011739 │
│ AsynchronousReadWaitMicroseconds            │    2380284 │    2025078 │      -0.7018702173136342 │
│ NetworkReceiveBytes                         │        516 │        372 │      -1.4210676174531387 │
└─────────────────────────────────────────────┴────────────┴────────────┴──────────────────────────┘

26 rows in set. Elapsed: 0.173 sec. Processed 5.86 million rows, 2.40 GB (33.92 million rows/s., 13.92 GB/s.)

Pricing​

For pricing information see the ClickHouse Cloud Pricing page. To understand what can affect your bill, and ways that you can manage your spend, keep reading.

Amazon Web Services(AWS) Examples​

Development: From $51 per month​

Best for: Starter projects & staging

• Development service
• 16 GiB RAM, 2 vCPU
• 1 TB Data

Pricing breakdown for this example:​

Production (Idling, Auto-scaling): From $172 per month​

Best for: Cost-sensitive ad-hoc analytics applications​

• Production Service
• Active workload ~25% time
• Idling on with default settings
• Auto-scaling maximum set to prevent runaway bills

Pricing breakdown for this example:​

Production (Always-on, Reserved capacity): From $550 per month​​

Best for: Latency-sensitive applications

• Production Service
• Active workload ~100% time
• Auto-scaling minimum set to reserve capacity

Pricing breakdown for this example:​

For help with further estimation, please contact support if you are already a ClickHouse Cloud user, or [email protected] otherwise.

Google Cloud Platform(GCP) Examples​

Development: From $46 per month​

Best for: Starter projects & staging

• Development service
• 16 GiB RAM, 2 vCPU
• 1 TB Data

Pricing breakdown for this example:​

Production (Idling, Auto-scaling): From $146 per month​

Best for: Cost-sensitive ad-hoc analytics applications​

• Production Service
• Active workload ~25% time
• Idling on with default settings
• Auto-scaling maximum set to prevent runaway bills

Pricing breakdown for this example:​

Production (Always-on, Reserved capacity): From $463 per month​​

Best for: Latency-sensitive applications

• Production Service
• Active workload ~100% time
• Auto-scaling minimum set to reserve capacity

Pricing breakdown for this example:​

For help with further estimation, please contact support if you are already a ClickHouse Cloud user, or [email protected] otherwise.

FAQs​

How is compute metered?​

ClickHouse Cloud meters compute on a per-minute basis, in 8G RAM increments.

How is storage on disk calculated?​

ClickHouse Cloud uses cloud object storage and is metered on the compressed size of data stored in ClickHouse tables.

Do backups count toward total storage?​

ClickHouse Cloud offers two free backups for production services, and one free backup for development services. Backups do not count toward storage.

How do I estimate compression?​

Compression can vary quite a bit by dataset. It is dependent on how compressible the data is in the first place (number of high vs. low cardinality fields), and how the user sets up the schema (using optional codecs or not, for instance). It can be on the order of 10x for common types of analytical data, but it can be significantly lower or higher as well. See the optimizing documentation for guidance and this Uber blog for a detailed logging use case example. The only practical way to know exactly is to ingest your dataset into ClickHouse and compare the size of the dataset with the size stored in ClickHouse.

You can use the query SELECT formatReadableSize(total_bytes) FROM system.tables WHERE name = <your table name>.

What tools does ClickHouse offer to estimate the cost of running a service in the cloud if I have a self-managed deployment?​

The ClickHouse query log captures key metrics that can be used to estimate the cost of running a workload in ClickHouse Cloud. For details on migrating from self-managed to ClickHouse Cloud please refer to the migration documentation, and contact ClickHouse Cloud support if you have further questions.

What billing options are available for ClickHouse Cloud?​

ClickHouse Cloud supports the following billing options:

• Self-service monthly (in USD, via credit card)
• Direct-sales annual / multi-year (through pre-paid "ClickHouse Credits", in USD, with additional payment options)

How long is the billing cycle?​

Billing follows a monthly billing cycle and the start date is tracked as the date when the ClickHouse Cloud organization was created.

What controls does ClickHouse Cloud offer to manage costs for Production services?​

• Trial and Annual Commit customers will be notified with automated emails when the consumption hits certain thresholds-50%, 75%, and 90%, so that users can take action.
• ClickHouse Cloud allows users to set a maximum auto-scaling limit on their compute via Advanced scaling control, a significant cost factor for analytical workloads.
• The Advanced scaling control lets you set memory limits with an option to control the behavior of pausing/idling during inactivity.

What controls does ClickHouse Cloud offer to manage costs for Developer services?​

• The Advanced scaling control lets you control the behavior of pausing/idling during inactivity. Adjusting memory allocation is not supported for Developer services
• Note that the default setting pauses the service after a period of inactivity

If I have multiple services, do I get an invoice per service or a consolidated invoice?​

A consolidated invoice is generated for all services in a given organization for a billing period.

If I add my credit card and upgrade before my trial period and credits expire, will I be charged?​

When a user converts from trial to paid before the 30-day trial period ends, but with credits remaining from the trial credit allowance, we continue to draw down from the trial credits during the initial 30-day trial period, and then charge the credit card.

How can I keep track of my spending?​

ClickHouse Cloud console includes a Usage display that gives detailed information about usage per service on compute and storage. This can be used to understand the cost breakdown by metered units.

How do I access my invoice for my AWS marketplace subscription to the ClickHouse Cloud service?​

All marketplace subscriptions will be billed and invoiced by AWS. You can download the invoice from the AWS Billing Dashboard.

Why do the dates on the Usage statements not match my AWS Marketplace Invoice?​

AWS Marketplace billing follows the calendar month cycle e.g., for usage between dates 01-Dec-2022 and 01-Jan-2023, an invoice will be generated between 3-Jan and 5-Jan-2023

ClickHouse Cloud usage statements follow a different billing cycle where usage is metered and reported over 30 days starting from the day of sign up

The usage and invoice dates will differ if these dates are not the same. Since usage statements track usage by day for a given service, users can rely on statements to see the breakdown of costs.

Are there any restrictions around the usage of prepaid credits?​

ClickHouse Cloud prepaid credits (whether direct through ClickHouse, or via a cloud provider's marketplace) can only be leveraged for the terms of the contract. This means they can be applied on the acceptance date, or a future date, and not for any prior periods. Any overages not covered by prepaid credits must be covered by a credit card payment, or marketplace monthly billing.

You can subscribe to ClickHouse Cloud through the AWS, GCP, and Azure marketplaces. This allows you to pay for ClickHouse Cloud through your existing cloud provider billing.

You can either use pay-as-you-go (PAYG) or commit to a contract with ClickHouse Cloud through the marketplace. The billing will be handled by the cloud provider, and you will receive a single invoice for all your cloud services.

• AWS Marketplace PAYG
• AWS Marketplace Committed Contract
• GCP Marketplace PAYG
• GCP Marketplace Committed Contract
• Azure Marketplace PAYG
• Azure Marketplace Committed Contract

FAQs​

How can I verify that my organization is connected to marketplace billing?​

In the ClickHouse Cloud console, navigate to Billing. You should see the name of the marketplace and the link in the Payment details section.

I am an existing ClickHouse Cloud user. What happens when I subscribe to ClickHouse Cloud via AWS / GCP / Azure marketplace?​

Signing up for ClickHouse Cloud from the cloud provider marketplace is a two step process:

1. You first "subscribe" to ClickHouse Cloud on the cloud providers' marketplace portal. After you have finished subscribing, you click on "Pay Now" or "Manage on Provider" (depending on the marketplace). This redirects you to ClickHouse Cloud.
2. On Clickhouse Cloud you either register for a new account, or sign in with an existing account. Either way, a new ClickHouse Cloud organization will be created for you which is tied to your marketplace billing.

NOTE: Your existing services and organizations from any prior ClickHouse Cloud signups will remain and they will not be connected to the marketplace billing. ClickHouse Cloud allows you to use the same account to manage multiple organization, each with different billing.

You can switch between organizations from the bottom left menu of the ClickHouse Cloud console.

I am an existing ClickHouse Cloud user. What should I do if I want my existing services to be billed via marketplace?​

Please contact ClickHouse Cloud support in this case. You will need to subscribe to ClickHouse Cloud via the marketplace and we can switch organization linkage to resources so that billing happens via the marketplace.

I subscribed to ClickHouse Cloud as a marketplace user. How can I unsubscribe?​

Note that you can simply stop using ClickHouse Cloud and delete all existing ClickHouse Cloud services. Even though the subscription will still be active, you will not be paying anything as ClickHouse Cloud doesn't have any recurring fees.

If you want to unsubscribe, please navigate to the Cloud Provider console and cancel the subscription renewal there. Once the subscription ends, all existing services will be stopped and you will be prompted to add a credit card. If no card was added, after two weeks all existing services will be deleted.

I subscribed to ClickHouse Cloud as a marketplace user, and then unsubscribed. Now I want to subscribe back, what is the process?​

In that case please subscribe to the ClickHouse Cloud as usual (see sections on subscribing to ClickHouse Cloud via the marketplace).

• For AWS marketplace a new ClickHouse Cloud organization will be created and connected to the marketplace.
• For the GCP marketplace your old organization will be reactivated.

If you have any trouble with reactivating your marketplace org, please contact ClickHouse Cloud Support.

How do I access my invoice for my marketplace subscription to the ClickHouse Cloud service?​

• AWS billing Console
• GCP Marketplace orders (select the billing account that you used for subscription)

Why do the dates on the Usage statements not match my Marketplace Invoice?​

Marketplace billing follows the calendar month cycle. For example, for usage between December 1st and January 1st, an invoice will be generated between January 3rd and January 5th.

ClickHouse Cloud usage statements follow a different billing cycle where usage is metered and reported over 30 days starting from the day of sign up.

The usage and invoice dates will differ if these dates are not the same. Since usage statements track usage by day for a given service, users can rely on statements to see the breakdown of costs.

Where can I find general billing information​?

Please see the Billing overview page.

The root cause of these permissions errors has been identified and is due to more strict checking of grants in the new release for async_inserts.

To fix this issue, grants must be updated for your service to work. Check the error message indicating the missing grants and add those needed grants manually. The required additional grants for the tables using async_inserts will either be the SELECT or dictGet grant.

Add necessary GRANTs to affected tables and dictionaries​

-- Add SELECT grant permissions
GRANT SELECT ON mydb.insertTable TO insert_role WITH GRANT OPTION

-- Add dictGet grant permissions
GRANT dictGet ON mydb.insertDictionary TO insert_role

To learn more about the GRANT command, please see this page.

If you are unable to perform this change, then please contact ClickHouse Support for assistance.