Legal
Privacy policy
The short version. This is a one-page site about a book. It has no accounts, no sign-up, no newsletter, no comments and no forms, so there is nothing here for you to submit and nothing of yours for it to keep. The only thing it would like to do is count visits. In the EEA, the UK and Switzerland that counting does not start until you press Accept, and if you decline or ignore the question, it never starts at all.
Who is responsible
This site, linuxperformancebook.com, is run by Ayan Kumar Nath,
the author of Linux Performance (BPB Publications, 2026). For anything
on this page, including any request about your data, the contact address is
ayan@linuxperformancebook.com.
The site is published as static files. There is no database, no server-side application and no login, here or behind the scenes.
What is collected
1. Google Analytics — optional, and off until you allow it
If you allow it, Google Analytics 4 records that a page was viewed, along with the standard technical information a browser sends: approximate location derived from your IP address, device and browser type, screen size, language, and the page you arrived from. It sets the cookies listed below.
If you are in the EEA, the UK or Switzerland, none of this happens unless you press Accept. Until then no Google script is even requested, so nothing is loaded and no cookie is set. Declining, or simply ignoring the bar, both leave analytics switched off. You can change your mind at any time using the Analytics cookies control in the footer of every page.
Elsewhere in the world, analytics start when the page loads. The same footer control turns them off.
2. Cloudflare Web Analytics — no cookies, no identifier
The site also uses Cloudflare Web Analytics, which counts page views without setting any cookie, without storing anything on your device and without any identifier that could follow you to another site. Because it cannot recognise you, it is not something you are asked to consent to, and it cannot be used to build a profile.
3. Hosting and security
The site is hosted on Cloudflare Pages and served through Cloudflare's network. Like any web host, Cloudflare processes your IP address and request details in order to deliver the page and to protect the site from attack and abuse. This is ordinary server operation and happens for every visitor.
4. Your own choice about analytics
When you answer the analytics question, the answer is saved in your
browser's local storage under the name lpb-consent, so that you
are not asked again on every page. It records only your answer and the date.
It is not a cookie, is never sent to the site or to anyone else, and can be
cleared at any time by clearing site data in your browser.
Cookies and local storage in full
| Name | Set by | Purpose | Expires |
|---|---|---|---|
_ga |
Google Analytics | Distinguishes one browser from another so repeat visits are not counted twice | 2 years |
_ga_ZPK8DV2LNN |
Google Analytics | Keeps the state of the current visit | 2 years |
lpb-consentlocal storage, not a cookie |
This site | Remembers whether you allowed analytics, so you are not asked repeatedly | 12 months, then you are asked again |
That is the complete list. If you have not allowed analytics, the first two are never set, and the third exists only if you have answered the question. The site itself sets no cookies of its own.
What this site does not do
- No accounts, logins, forms, comments or newsletter. Nothing to fill in.
- No advertising, no advertising networks and no retargeting pixels.
- Your data is never sold, rented or traded. There is no such arrangement with anyone.
- No automated decision-making and no profiling that produces any effect on you.
- No attempt to identify you personally. The author has no way to tell who any individual visitor is, and does not want to.
Why this is allowed — the legal basis
For readers in the EEA, the UK and Switzerland:
- Google Analytics: your consent (UK/EU GDPR Article 6(1)(a)). It is requested before anything loads, it is entirely optional, and it can be withdrawn at any time from the footer of any page. Withdrawing is as easy as giving it, and takes effect immediately.
- Hosting, security and cookieless counting: legitimate interests (Article 6(1)(f)) — namely serving the site reliably, keeping it available, and knowing in aggregate how many people read it. None of this identifies you or stores anything on your device.
Who else is involved
Two processors, and no others:
- Google (Google Ireland Limited / Google LLC), for Google Analytics, and only if you allowed it.
- Cloudflare (Cloudflare, Inc.), which hosts and serves the site and provides the cookieless analytics.
Both are based in, or transfer data to, the United States. Those transfers rely on the safeguards those companies publish for the purpose, including the EU Standard Contractual Clauses and the EU–US Data Privacy Framework.
Links to shops and other sites
This site sends you to other places to buy the book, including BPB Online, Amazon, Google Play and other retailers. Once you follow one of those links you are on someone else's site, under their privacy policy, and they will do their own tracking. That is outside this site's control.
Some Amazon links carry an affiliate tag, which means the author may earn a small commission if you buy. It costs you nothing and does not change the price. The tag tells Amazon the visit came from this site; it tells this site nothing about you, and no information about you is passed to Amazon by the link.
How long anything is kept
Google Analytics keeps event data for the retention period configured on the property, which is at most 14 months, after which Google deletes it. Cloudflare's cookieless analytics are aggregate counts and hold nothing attributable to you. Your consent choice stays in your own browser for twelve months, or until you clear it, and never leaves your device.
Your rights
If you are in the UK, the EEA or Switzerland, you have the right to ask for access to any personal data held about you, to have it corrected or erased, to restrict or object to its use, to receive it in a portable form, and to withdraw consent at any time.
In practice the fastest and most complete way to exercise most of these here is the Analytics cookies control in the footer: declining stops the collection and deletes the analytics cookies from your browser immediately. For anything further, write to ayan@linuxperformancebook.com and it will be answered within one month.
Be aware of an honest limitation: because this site never learns who you are, a request to access or erase "your" data usually cannot be matched to any particular record. What can be done is to stop further collection and delete what is on your device, and that is done immediately on request.
If you believe your data has been mishandled you can complain to your data protection authority. In the UK that is the Information Commissioner's Office (ico.org.uk); in the EEA it is the supervisory authority of the country you live in.
Children
This is a technical book for working engineers. The site is not directed at children and does not knowingly collect anything from them.
Changes
If this policy changes in a way that affects what is collected or why, the date at the top will change and, where consent is involved, you will be asked again rather than assumed to have agreed.
Contact
Ayan Kumar Nath
ayan@linuxperformancebook.com